Irreversible Investment under Dynamic Agencyfaculty.arts.ubc.ca/pnorman/CETC/Papers/contract.pdf ·...
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Irreversible Investment under Dynamic Agency∗
Steven R. Grenadier†, Jianjun Miao‡, and Neng Wang§
December 2004
Abstract
This paper provides a recursive contracting model to analyze the irreversible investmentdecision for a decentralized firm when the manager has private information about the invest-ment cash flows. We show that compared to the full information benchmark, investment isdelayed under asymmetric information. We also show that managerial risk aversion lowersthe option value of waiting and increases information rents. The net effect of risk aversionis to delay investment. The model also predicts that according to the optimal contract, theowner punishes the manager by lowering his compensation over time when the manager doesnot invest, and rewards the manager when he makes the investment. The reward increaseswith the profits upon investing.
Keywords: irreversible investment, information asymmetry, dynamic agency, recursivecontracts, real options.
∗We thank seminar participants in Boston University for helpful comments, especially, Simon Gilchrist, LarryKotlikoff, Kevin Lang, Rasmus Lents, Bart Lipman, and Michael Manove.
†Graduate School of Business, Stanford University, Stanford, CA 94305 and National Bureau of EconomicResearch, Cambridge, MA, USA. Email: [email protected]. Tel.: 650-725-0706.
‡Department of Economics, Boston University, 270 Bay State Road, Boston, MA 02215. Email:[email protected]. Tel.: 617-353-6675.
§Columbia Business School, 3022 Broadway, Uris Hall 812, New York, NY 10027. Email:[email protected]; Tel.: 212-854-3869.
1 Introduction
One of the most important topics in corporate finance and macroeconomics is the formulation of
the optimal investment strategies of firms. The investment decision has two components: how
much to invest and when to invest. The first is the capital allocation decision, and the second is
the investment timing decision. The standard textbook prescription for the capital allocation
decision is that firms should invest in an amount such that the marginal product of capital is
equal to the user cost of capital. The standard theory for the investment timing decision is that
firms should invest in projects when their net present values (NPVs) are positive. Recently,
the alternative real options approach has been widely accepted. The real options approach
posits that the opportunity to invest in a project is analogous to an American call option on
the investment project, and the timing of investment is economically equivalent to the optimal
exercise decision for an option. This real options approach is well summarized in Dixit and
Pindyck (1994) and Trigeorgis (1996).
Both the user cost theory and the standard real options approach fail to account for the
presence of conflicts of interests induced by information asymmetries between the owner and the
delegated manager. In most modern corporations, shareholders delegate the investment decision
to managers, using managers’ special skills and expertise. In such decentralized settings, there
are likely to be information asymmetries. In general, managers are better informed than owners
about project cash flows. A number of papers in the literature provide models of capital
budgeting under asymmetric information and agency.1 The focus of this literature is on the first
element of the investment decision: the amount of capital allocated to managers for investment.
Thus, this literature provides predictions on whether firms over- or under-invest relative to
the first-best no-agency benchmark. The focus of this paper is on the second element of the
investment decision: the timing of investment. We extend the real options framework to account
for the issues of information and agency in a decentralized firm. Analogous to the notions of
over- or under-investment, our paper provides results on hurried or delayed investment.
No agency conflicts arise in the standard real options paradigm since it is assumed that
the option’s owner makes the exercise decision.2 By contrast, in this paper, a risk-neutral
1See Stein (2003) for a summary.2While our paper focuses on the agency issues that arise from the conflict of interests between owners and
managers, similar issues exist between stockholders and bondholders.
1
owner delegates the option exercise decision to a risk averse manager. The owner’s problem
is to design an optimal contract under asymmetric information. Absent any mechanism that
induces the manager to reveal his private information voluntarily, the manager could have an
incentive to lie about the true level of the project cash flows and divert cash flows for his
private interests. For example, the manager could divert privately observed cash flows by
consuming excessive perquisites or building empires. To overcome these problems, an optimal
contract selects an investment rule and designs a compensation scheme to the manger so as to
maximize the owner’s value such that the manager follows voluntarily this investment rule and
his behavior is incentive compatible. Since the manager is risk averse, the owner will provide
partial consumption insurance to the manager in order to facilitate the manager to smooth his
intertemporal consumption. An optimal contact must trade off insurance against incentives.
Briefly summarized, unlike traditional real options models, our model incorporates at least two
important real-world features into dynamic real option models: managerial risk aversion and
informational asymmetry, using the optimal contracting approach. We show that these two
features jointly generate new and interesting implications for the investment timing decision
and the dynamics of managerial compensation.
Our model implies that investment behavior differs substantially from the one implied by the
standard real options approach with no agency problems. We show that the manager displays
greater inertia in their investment behavior, in that they invest later than implied by the first-
best solution. This is because of the agency cost induced by informational asymmetry. The
agency cost reflects the fact that the manager captures some rents from his private information
about the investment project. By waiting longer, the owner saves more information rents to
the manager. Importantly, managerial risk aversion affects the investment timing decision in
two opposite ways. First, a larger degree of risk aversion lowers the manager’s option value of
waiting due to partial insurance or market incompleteness.3 This result has been obtained by
Miao and Wang (2004) in a dynamic incomplete-markets real options model without agency
issues. Second, the information rents captured by the manager increases with risk aversion. Our
extensive numerical exercises indicate that the latter agency cost effect dominates the former.
3In the standard real options approach, capital markets are assumed to be complete. By the standard arbitrageargument, the option value and investment timing are independent of preferences (see Dixit and Pindyck (1994)).In the conracting framework, this result also holds true if the owner fully insures the manager, as shown inProposition 2.
2
Thus, we find that investment is delayed and is delayed more if the manager is more risk averse.
In addition to generating predictions on investment decisions, our model also provides pre-
dictions on the dynamic evolution of managerial compensation. We show that managerial
compensation decreases over time before investment is made and increases when the manager
invests. Moreover, the amount of increase in managerial compensation depends on the cash
flows generated by the project. This increase in managerial compensation upon investment
provides an agency based explanation to the observation that the manager is rewarded with
bonus upon completion of successful projects. Finally, our model also predicts that firm value
jumps upwards when the manager invests. This is consistent with the empirical finding that
the announcements of unexpected increases in investment lead to increases in stock prices, as
documented by McConnell and Muscarella (1985).
Since our model allows for repeated interactions between the manager and the owner in a
long-term relationship, the contracting problem becomes inherently dynamic and the optimal
contract potentially depends on the history of the manager’s reported cash flows. In order
to keep the model analytically tractable, we use the techniques developed in the recursive
contracting literature.4 The key insight of the recursive contracting methodology is to capture
the history dependence of dynamic relationship between the owner and the manager by using
a state variable so that one can formulate the history-dependent optimal contacting problem
as a recursive one. This important state variable is the promised value by the owner to the
manager. The promised value describes the manager’s lifetime utility from the consumption
(or compensation) stream delivered by the owner. It is not only a forward looking variable, but
also summarizes the histories relevant for contracting purposes.
The paper closely related to ours is Grenadier and Wang (2004). They also analyze how
informational asymmetry and agency conflicts distort investment timing decisions. Grenadier
and Wang (2004) assume that the owner pays the manager only at the time of investment,
and specify managerial compensation contingent upon the manager’s announced cash flows of
4See Abreu, Pearce and Stacchetti (1990), Green (1987), Spear and Srivastava (1987), Thomas and Worrall(1988, 1990) for seminal contributions. The recursive contract approach has been applied widely in macroeco-nomics recently, e.g., unemployment insurance (Hopenhayn and Nicolini (1997) and Shimer and Werning (2003)),taxation (Kocherlakota (2004)), and social insurance (Atkeson and Lucas (1992)). Albuquerque and Hopenhayn(2004) and Clementi and Hopenhayn (2002) study the optimal lending contracts by analyzing the conflict of in-terests between borrowers and lenders. See Ljungquist and Sargent (2004) for a textbook treatment on recursivecontracts.
3
the project at the time of investment. In our setting, the owner and the manager interact
repeatedly in a long-term relationship. The optimal contract requires the owner to pay the
manager even if the manager does not invest, since the manager is risk averse and compensating
the manager before his investment smooths his intertemporal consumption. Thus, the key
predictions of our model rely heavily on managerial preferences for intertemporal consumption
smoothing, induced by risk aversion. This leads to the next key distinction between our model
and Grenadier and Wang (2004), who assume that managers are risk neutral and are protected
by limited liability. Finally, unlike Grenadier and Wang (2004) who analyze the effects of both
informational asymmetry and moral hazard on the investment timing decision, we focus on the
role of informational asymmetry only.
Our work also relates to the capital budgeting literature, particularly to Harris and Ra-
viv (1996, 1998) and Bernardo, Cai, and Luo (2001).5 Harris and Raviv (1996) apply a static
costly state verification model to examine capital budgeting processes in a single-division firm.
Harris and Raviv (1998) generalize that model to a multi-division firm. Both papers assume
that all parties are risk neutral and that managerial compensation is exogenous. Bernardo,
Cai, and Luo (2001) consider the capital allocation decision for a decentralized firm under both
asymmetric information and moral hazard in a static model. They use the optimal contract-
ing approach to jointly derive the optimal investment and compensation policies. Unlike the
preceding papers, we analyze the (irreversible) investment timing decision in a dynamic frame-
work. As in Bernardo, Cai, and Luo (2001), we derive managerial compensation as part of the
optimal contract. However, our dynamic model has important implications for the dynamics
of managerial compensation.
The remainder of the paper is organized as follows. Section 2 presents and solves the optimal
contracting problem in a static model. Section 3 introduces the dynamic setting and solves for
the optimal contract using recursive methods. Section 4 analyzes the model’s implications
on investment decision and wage dynamics. Section 5 concludes. Proofs are relegated to an
appendix.
5See Harris et al. (1982), Antle and Eppen (1985), and Holmstrom and Ricart i Costa (1986) for related earlywork.
4
2 A Static Model
We first solve for the optimal contract in a static setting, which provides intuition for the nature
of dynamic contract analyzed in Section 3. Consider a decentralized firm. The risk-neutral
owner of the firm has an investment project. The project costs I and generates a stochastic
project value x, which is randomly drawn from a given distribution function F (x) over the
interval [a, b]. Assume that F has a positive continuously differentiable density f > 0 and
I ∈ (a, b) .6 The owner delegates the investment decision to the manager because the manager
has special human capital. The manager decides whether to invest in the project or not. The
manager is risk averse with an increasing, strictly concave and continuously differentiable utility
function u.
The manager and the owner sign a contract. The key assumption is that the manager has
private information about the project value, and thus has incentives to lie in order to hide
project value from the owner. An optimal contract induces the manager to truthfully reveal his
privately observed project value. Moreover, the contract also ought to provide some insurance
to the manager since the manager is risk averse and the owner is risk neutral. These two goals
often come into conflicts. For example, a fully insured manager has no incentives to reveal his
project value truthfully, when he has a high project value. We will show later that the optimal
contract trades off incentive elicitation against insurance provision. Intuitively, one should
expect that managerial compensation must be tied to the manager’s investment decision and
his reported project value, while partially help the manager smooth his consumption across
states.
The optimal contracting problem can be described formally as a mechanism design problem
or a message game. By the revelation principle, we can restrict to the direct revelation mecha-
nism in which the message space is the set of possible project values. The manager’s investment
decision is binary. The contract specifies an investment rule with a threshold value x such that
the investment is made if and only if the reported project value is above the threshold x. Sup-
pose that the manager observes the project value is x. If he reports a high value x̃ ≥ x to the
owner, the owner pays the manager a wage yA (x̃) and the manager must make the investment
6It will be clear below that the assumption on f ensures the existence of a solution under asymmetric in-formation. The assumption on investment cost I rules out the uninteresting case where the project is eitherinvested immediately or never invested.
5
and give the owner the reported project value. If the manager reports a low value x̃ < x, then
the owner pays him a wage yA (x̃) and the manager does not invest.
An optimal contract maximizes the owner’s value (or firm value) subject to meeting the
manager’s participation and truth-telling incentive constraints. Formally, we formulate the
contracting problem as
max(yA,yB ,x)
−
∫ x̄
a
yB (x) dF (x) +
∫ b
x̄
[x − yA (x) − I
]dF (x) (1)
subject to
v =
∫ x̄
a
u(yB (x)
)dF (x) +
∫ b
x̄
u(yA (x)
)dF (x) , (2)
and
u(yA (x)
)≥ u
(yA (x̃) + x − x̃
), x, x̃ ≥ x̄, (3)
u(yA (x)
)≥ u
(yB (x̃)
), x ≥ x̄ > x̃, (4)
u(yB (x)
)≥ u
(yA (x̃) + x − x̃
), x̃ ≥ x̄ > x, (5)
u(yB (x)
)≥ u
(yB (x̃)
), x̄ > x, x̃. (6)
Equation (2) is the individual rationality constraint which describes that the participating
manager has a reservation utility level v. Inequalities (3)-(6) are incentive constraints. For
example, the left side of inequality (3) states that the manager with project value x ≥ x̄, will
invest and receive compensation yA (x). The right side of (3) gives the utility for the manager if
he lies and reports x̃ ≥ x̄. Under such a scenario, the manager can hide the part of project value
(x − x̃) and receive compensation yA (x̃). Incentive constraint (3) ensures that the manager has
no incentive to lie to any x̃ ≥ x̄. The other three incentive constraints rule out the manager’s
incentives to lie in other situations. For notational convenience, let dA (x) = x − yA (x) denote
the dividend payment to the owner, when the manager invests.
The following lemma simplifies the incentive constraints.
Lemma 1 If the manager does not invest, then he receives constant compensation yB, which
is independent of the reported project value, in that yB(x) = yB(x̃) = yB, for x, x̃ < x̄. If
the manager invests, then the owner receives constant dividend dA, which is independent of the
reported project value x, in that dA(x) = dA(x̃) = dA, for x, x̃ ≥ x̄. Moreover, yB = yA (x̄) =
x̄ − dA.
6
The intuition behind the above lemma is as follows. Since the owner cannot observe the
project value, the optimal contract must be designed in such a way that the owner’s payoff may
only depend on the manager’s observable and verifiable investment/no-investment decision, and
cannot respond to the manager’s private information beyond what is conveyed by the managerial
investment decision. If the manager invests, the payoff for the owner is dA(x) = x − yA(x). If
the manager does not invest, then the owner pays the manager compensation yB (x). Lemma 1
shows that both yB and dA are constant, consistent with our intuition. It is worth noting that
the constancy of yB and dA does not hinge upon the manager’s risk aversion and solely derives
from incentive compatibility conditions. Finally, when the project value is at the threshold x̄,
the manager is indifferent between investing and not investing, and hence receives the same
compensation yB = yA (x̄) = x̄ − dA.
Using Lemma 1, we can simplify the optimal contracting problem as follows:
max(dA,x)
−(x̄ − dA
)F (x̄) +
(dA − I
)(1 − F (x̄)) (7)
subject to
v = u(x̄ − dA
)F (x̄) +
∫ b
x̄
u(x − dA
)dF (x) . (8)
Proposition 1 In the static model with asymmetric information, the optimal contract is as
follows. (i) The optimal trigger x̄∗ and the dividend payment dA satisfy the equation
x̄∗ − I =F (x̄∗)
f (x̄∗)
[λu′
(x̄∗ − dA
)− 1
], (9)
and the participation constraint (2), where
λ−1 = u′(x̄∗ − dA
)F (x̄) +
∫ b
x̄∗
u′(x − dA
)dF (x) . (10)
(ii) For x < x̄∗, the manager does not invest, and receives constant compensation yB = x̄∗−dA.
For x ≥ x̄∗, the manager invests and receives compensation yA(x) = x − dA.
Before we explain the optimal contract described in this proposition, we first outline the
efficient investment rule under symmetric information. Under symmetric information, there are
no incentive constraints (3)-(6). One can easily show that the investment trigger is equal to
the investment cost I, which is also the trigger value under the standard NPV rule. Moreover,
7
the owner fully insures the manager. That is, the owner offers a constant identical wage to the
manager no matter whether he makes the investment.
We now turn to the optimal contract under asymmetric information described in Proposition
1. Part (i) demonstrates that the investment trigger and compensation are jointly determined
by equations (9) and (2). To better understand equation (9), we rewrite it as
f (x̄∗) (x̄∗ − I) = F (x̄∗)[λu′
(x̄∗ − dA
)− 1
]. (11)
The left side of this equation represents the marginal cost from an additional unit increase in
the investment threshold. The cost arises because low “type” managers x < x̄∗ do not invest
at project values below x̄∗ and thus the NPV (x̄∗ − I) is lost. It is multiplied by f (x̄∗) which
represents the probability of this cost. The right side of the preceding equation represents the
marginal benefit. The benefit arises because the owner saves information rents λu′(x̄∗ − dA
)−1
to each “type” x below x̄∗. This happens with probability F (x̄∗) . Note that λ is the Lagrange
multiplier associated with the participation constraint (8). It represents the shadow price of
the reservation utility.
Given the above discussion, we interpret the right side of (9) as information rents or agency
costs due to asymmetric information. Managerial risk aversion (u′′(x) < 0) implies that these
agency costs are positive, and thus the investment trigger is higher than the cost of investment
(x̄∗ > I). Consequently, the investment threshold under asymmetry information is higher than
that in the full information benchmark. This means that asymmetric information leads to
underinvestment. The intuition is the following. When designing an optimal contract, the
owner faces the trade off between providing insurance and eliciting incentives. He must offer
information rents to the privately informed manager such that he will not lie. This generates
agency costs and distorts investment efficiency. Note that if the manager is risk neutral, then
investment will be efficient because the manager is equally capable of bearing risk as the owner
does.
Part (ii) of Proposition 1 demonstrates that the owner offers a constant wage yB to the
manager if he does not make the investment. However, the manger is rewarded if he makes
the investment. Moreover, the wage yA is positively related to the project value. Thus, wage
provides incentives to the manager such that he tells the owner the true project value and makes
the investment. In addition, the wage must also provide insurance to the risk averse manager.
8
Because of incentive problems, the manager does not obtain constant full insurance wage.
We now turn to the question as to how managerial risk aversion influences investment deci-
sion. Unfortunately, we cannot derive a general result analytically for general utility functions.
The constant absolute risk aversion (CARA) utility u (c) = −e−γc/γ is an exception, as shown
in the following Corollary. Before presenting it, we define the certainty equivalent η (x̄; γ) for
a lottery offering the payoff of max {x − x̄, 0}, where x is drawn from the distribution F .7 For
CARA utility, it is immediate to show that
η (x̄; γ) =
{− 1
γlog
[F (x̄) +
∫ b
x̄e−γ(x−x̄)dF (x)
], γ > 0,
∫ b
x̄(x − x̄) dF (x), γ = 0.
(12)
Corollary 1 Suppose u (c) = −e−γc/γ. (i) If [1 − F (x) + η′ (x; γ)] /f (x) is decreasing in x ∈
[a, b] , then the optimal trigger value x̄∗ is the unique solution to the equation
x̄∗ − I =1 − F (x̄∗) + η′ (x̄∗; γ)
f (x̄∗). (13)
Moreover, x̄∗ is increasing in γ. (ii)The optimal compensation policy is given by
yB = −1
γlog (−vγ) − η (x̄∗; γ) for x < x̄∗, (14)
yA (x) = x − x̄∗ + yB for x ≥ x̄∗ . (15)
Notice that for CARA utility, the investment trigger is determined by a single equation,
independent of compensation and reservation utility. This is because CARA utility has no
wealth effect. This feature is more important when we turn to the dynamic contract in Section
3. Thus, in most of analysis below we will adopt this utility specification.
The intuition behind Corollary 1 is the following. When risk aversion is higher, the manager
prefers to have smoother consumption. This insurance objective is in conflict with the truth-
telling incentives. In order to elicit incentives, the owner must offer more information rents to
the manager. Thus, agency costs are higher; that is, the term on the right-hand side of (13)
is higher. This implies investment is distorted more in the sense that the investment trigger is
higher.
This intuition carries over for the constant relative risk aversion utility specification u (c) =
c1−γ/ (1 − γ) , γ ≥ 0. We illustrate this point by numerical simulations. We choose a standard
7Use u(η) = E [u (max {x − x̄, 0})], where u is CARA utility.
9
uniform distribution over [0,1] and set the investment cost I = 0.5. We also set the reservation
utility v = 0.11−γ/ (1 − γ) . That is, the manager receives a consumption level of 0.1 if he does
not participate in the contract.8 Figure 1 plots the investment threshold as a function of the
risk aversion parameter. This figure indicates that the investment threshold increases with the
risk aversion parameter.
[Insert Figure 1 Here]
In the next section, we turn to the dynamic setting. When the manager and the owner
live in a dynamic environment with repeated relationship, two important distinctions from the
static setting arise. First, there is an option value of waiting even in the absence of agency
issues. Second, the owner can use an intertemporal punishment and rewarding compensation
scheme to elicit incentives. We show that the interaction between the option value of waiting
and the intertemporal incentive scheme gives interesting implications for investment timing.
3 Optimal Recursive Contract
We begin this section by first describing the dynamic setting and formulating the problem in
a recursive manner. We then provide the solution to the first-best full-information investment
problem, as a benchmark for further analysis. Finally, we derive the solution to the recursive
contracting problem under asymmetric information.
3.1 Dynamic Setting
Unlike the static setting, the manager privately observes the project’s cash flows xt in each
period t = 0, 1, . . .. The project cash flows are independently and identically drawn from a
distribution function F over the interval [a, b] .9 If the manager invests at the cash flow value
x in some period τ , the firm pays the cost I immediately, and the project generates an equal
cash flow x in period τ and each period thereafter. This assumption simplifies the contracting
8Note that we do not choose a fixed utility level, say 0, as the reservation value. Otherwise, the manager willnot participate in the contract when his risk aversion is bigger than 1 since in any contract his utility is alwaysless than 0 given u (c) = c1−γ/ (1 − γ) specification. We rule out this situation in our numerical example.
9Assume that F has a positive continuously differentiable density f > 0 and I ∈ (a/ (1 − β) , b/ (1 − β)) . Itwill be clear below that the assumption on f ensures the existence of a solution under asymmetric information.The assumption on I rules out the uninteresting case where the project is either invested immediately or neverinvested. The IID assumption is important to formulate the optimal contract recursively.
10
problem after investment. In Section 4.4, we will relax this assumption. We also assume
that investment is irreversible in the sense that if the manager invests, he does not make any
investment decision again and forgoes all future opportunities to draw high values of cash flows.
As in the static setting, the owner delegates the investment decision to the manager. The risk
averse manager has a time-additive expected utility given by E[∑∞
t=0 βtu (ct)], where β ∈ [0, 1)
is the subjective discount factor. The owner is risk neutral and discounts cash flows according
to the discount factor β.
The owner does not observe the project cash flows, which are the manager’s private infor-
mation. However, the owner observes whether or not the manager has made the investment in
the previous periods. As is standard in the contracting literature, we assume that at time zero,
the owner makes a take-it-or-leave-it offer. The terms of the dynamic contract are contingent
on histories of the manager’s reports and investment status. Let st = 0 if the investment is
not made in period t and st = 1 if the investment is made in period t. Let xt = (x0, x1, ..., xt)
and st = (s0, s1, ..., st) denote the history of cash flows and the history of investment status,
respectively. Since the investment is irreversible, st satisfies the property that sτ = 1 for all
t′ ≤ τ ≤ t if t′ is the minimum τ such that sτ = 1. By the revelation principle, we can
restrict the manager’s reporting strategy to be a function of the form x̂ ={x̂t
(xt, st
)}∞
t=0.
The dynamic contract specifies an investment rule and a managerial compensation scheme con-
tingent on the histories of reports and investment status ht = (x̂0, s0; x̂1, s1; ...; x̂t, st) .10 The
optimal contract maximizes the owner’s expected discounted payoffs subject to the manager’s
intertemporal incentive and participation constraints.
As shown by Rogerson (1985) in a related two-period moral hazard model, an optimal dy-
namic contract depends on the history of reports. This history dependence makes the analysis
complicated. In order to tackle this problem, we follow the recursive contract literature and cre-
ate a state variable that summarizes the history of reports.11 Then, we may convert the history
dependent optimization problem into a recursive (Markovian) one. The newly created state
variable is the manager’s utility promised by the owner. Intuitively, the promised continuation
utility captures what the manager cares for his future. After all, the manager’s objective is
to maximize his life-time utility. Thus, using current compensation and promised continuation
10We will offer more detailed comments on this contract form in the next subsection.11See Spear and Srivastava (1987), Thomas and Worrall (1990) and Abreu et al (1990) for early contribution
to this approach.
11
utility, the owner is able to deliver the manager’s reservation value.
3.2 Recursive Formulation
We now describe the dynamic contract in a recursive manner. Specifically, consider any date
when investment has not been made before. Suppose at that date the manager is promised an
expected lifetime utility level v. The dynamic contract is described as follows:
1. The manager observes a value of cash flows x drawn from the distribution F ( · ) and then
makes a report x̃ to the owner.
2. The owner observes the report x̃ and recommends the manager to follow a trigger in-
vestment rule. Specifically, there is a threshold value x̄, such that the investment is
undertaken when the manager reports a high value x̃ ≥ x̄; and the investment is not
undertaken, otherwise.
3. If the investment is not undertaken, the owner offers the manager compensation yB (x̃) and
a promised continuation value wB (x̃) for the next period. If the investment is undertaken,
the manager obtains the true value of cash flows x and hands over the reported cash flows
x̃ to the owner in each period after investment. Moreover, the owner offers compensation
yAn (x̃) in the nth period after investment, n ≥ 0.
Two comments on the contract form are in order. First, as in the static model described
in Section 2, the dynamic contract specifies an investment threshold such that the investment
is made if the reported cash flows are higher than this threshold and if there is no investment
before. This investment rule is intuitive and related to the trigger policy in the standard
investment model without agency issues, e.g., McDonald and Siegel (1986) or its discrete time
variant described in the proof of Proposition 2 in the appendix. Thus, we are able to compare
the investment policy in our model with that in the standard model without agency issues.
Note that the investment trigger x̄ may depend on the state variable – promised utility v. In
Section 3.4, we will show that it is a constant independent of v under the CARA specification.
In Section 4.3 we will also consider the case where the investment policy is not written in the
contract and follows a simple NPV rule often recommended in practice. We will contrast the
resulting solution with the optimal contract. Second, after investment the owner knows that
12
the project cash flows are locked in at the reported value upon investment, even though he does
not know the true value.12 Thus, any non-flat reports after investment are irrelevant to the
owner. Consequently, the owner will offer wages in every period after investment, contingent
on the reported value x̃ at the time of investment only.
We solve the contracting problem by dynamic programming. Let P (v) denote the value
function of the owner or firm value. The optimal contract solves the following problem:
P (v) = max(yB ,wB ,yA
n ,x̄)
∫ x̄
a
[−yB (x) + βP
(wB (x)
)]dF (x) (16)
+
∫ b
x̄
[∞∑
n=0
βn(x − yA
n (x))− I
]dF (x)
subject to
v =
∫ x̄
a
[u
(yB (x)
)+ βwB (x)
]dF (x) +
∫ b
x̄
∞∑
n=0
βnu(yA
n (x))dF (x) (17)
and
∞∑
n=0
βnu(yA
n (x))
≥∞∑
n=0
βnu(x − x̃ + yA
n (x̃)), x, x̃ ≥ x̄, (18)
∞∑
n=0
βnu(yA
n (x))
≥ u(yB (x̃)
)+ βwB (x̃) , x ≥ x̄ > x̃, (19)
u(yB (x)
)+ βwB (x) ≥
∞∑
n=0
βnu(x − x̃ + yA
n (x̃)), x̃ ≥ x̄ > x, (20)
u(yB (x)
)+ βwB (x) ≥ u
(yB (x̃)
)+ βwB (x̃) , x̄ > x, x̃. (21)
The interpretation of the participation and incentive constraints (17)-(21) is similar to that
given in the previous section. When x < x̄, the manager does not invest. The owner offers
the manager compensation yB (x) in the current period and continuation utility wB (x). The
12As an example, suppose that the contracted trigger value is 5. The manager’s draw of cash flow value hasbeen below the trigger level 5 from the initial period to period 9. Thus, there is no investment before (andincluding) period 9. Suppose that the manager draws a high value 7 of cash flows in period 10. However, themanager reports the cash flow value to be 6 in period 10. According to the contract, the manager invests inperiod 10, and hands over the reported cash flow value 6 in period 10 and each period thereafter. But he obtainsthe true value 7 in period 10 and each period thereafter. The owner does not observe the true value, which is 7.If the manager decides to change his reported cash flow to another false level, say he reports 5 in period 12, thisnew report in period 12 is payoff irrelevant to the owner. The wage in any period after investment is contingenton the report 6.
13
owner does not receive any cash flow, but obtains continuation firm value P(wB (x)
). When
x ≥ x̄, the manager invests. The owner offers the manager compensation yAn (x) in the nth
period after investment. The owner pays the investment cost I at the time of investment and
obtains truthfully reported cash flows x in each period thereafter. By the principle of optimality,
summing up the owner’s value under both investment and no-investment regions and integrating
with respect to the distribution F give the owner’s current value function P (v) .
3.3 Full Information Benchmark
As a benchmark, we analyze the case in which the manager and the owner have symmetric infor-
mation about the cash flows. The optimal contract is the solution to the optimization problem
(16) subject to the promise-keeping constraint (17). The following proposition summarizes the
optimal contract.
Proposition 2 The optimal contract under full information is characterized as follows: (i)
The investment threshold xFB is the unique solution to the following equation:
xFB − (1 − β) I =β
1 − β
∫ b
xFB
(x − xFB
)dF (x) . (22)
(ii) The managerial compensations, yB (x) and yAn (x), before and after investment are equal
and given by yFB = u−1 ((1 − β) v) for all x and n. (iii) The continuation value if investment
is not made is given by wB (x) = v. Firm value is given by
P (v) =−u−1 (v (1 − β))
1 − β+
∫ b
xFB (x − (1 − β) I) dF (x)
(1 − β) [1 − βF (xFB)]. (23)
The interpretation of (22) is as follows. The left side of equation (22) represents the marginal
cost of waiting when increasing the threshold value xFB by one unit. This cost is the forgone
NPV of the project, measured in the flow sense. The right side of (22) represents the option
value of waiting for one more period to receive better draws x ≥ xFB. Equation (22) prescribes
the firm to invest at the threshold value xFB such that the marginal benefit from waiting for
one more period equals the marginal cost of waiting. Note that under full information, the
manager is fully insured and obtains constant wages. Thus, he behaves in a risk neutral way
and the investment threshold is independent of preferences. In fact, in the appendix we show
that xFB is equal to the investment trigger under risk neutrality.
14
For much of the remainder, we use the CARA utility. With such a utility specification, the
managerial compensation under first-best benchmark is given by yFB = − log (−vγ (1 − β)) /γ.
3.4 Model Solution
We now turn to the optimal contract under asymmetric information. We first simplify the
incentive constraints and derive some general properties of the contract.
Lemma 2 (i) The incentive constraints (19)-(21) can be replaced with the condition
u(yB (x)
)+ βwB (x) =
∞∑
n=0
βnu(yA
n (x̄))
for all x < x̄. (24)
(ii) Let dAn (x) = x− yA
n (x) . Suppose u (c) = −e−γc/γ. If P (·) is strictly concave and differen-
tiable, then at the optimum yB (x) and wB (x) are independent of x for all x < x, and dAn (x)
is independent of n and x for all x ≥ x, and n ≥ 0.
The intuition behind this lemma is similar to that behind Lemma 1. Before investment,
the manager does not receive any cash flows. Thus, offering a constant wage and a constant
continuation value to the manager can induce his truth-telling incentives. The resulting lifetime
utility of the manager is the same as that upon investment at the threshold value x̄, as shown
in (24). Moreover, under CARA specification the incentive constraint (18) is redundant. This
is because for the CARA utility the manager “type” variable x can be cancelled out in the
incentive constraint (18). Consequently, an optimal contract cannot distinguish the manager
upon investment and hence requires all types of manager to hand over identical dividends to
the owner. By this lemma, without risk of confusion we may simply use dA, yB, and wB to
denote dAn (x) , yB (x) , and wB (x) , respectively. Let wA (x) =
∑∞n=0 βnu
(yA
n (x))
denote the
continuation value after investment. We are now ready to present our main result.
Proposition 3 Suppose the assumptions in Corollary 1 hold. Then the optimal contract under
asymmetric information is characterized as follows:
(i) The trigger value x̄∗ is the unique solution to the equation
x̄∗ − (1 − β) I =β
1 − βη (x̄∗; γ) +
[1 − F (x̄∗) + η′ (x̄∗; γ)] [1 − βF (x̄∗)]
(1 − β) f (x̄∗). (25)
15
(ii) The optimal compensation policy is given by
yB = −1
γlog (−vγ (1 − β)) − η (x̄∗; γ) for x < x̄∗, (26)
yA (x) = x − x̄∗ + yB for x ≥ x̄∗ . (27)
(iii) The continuation values are given by
wB = v exp (γη (x̄∗; γ)) for x < x̄∗, (28)
wA (x) = v exp (γη (x̄∗; γ) − γ (x − x)) for x ≥ x̄∗. (29)
(iv) The owner’s value function is given by
P (v) =log (−vγ (1 − β))
γ (1 − β)+
(x̄∗ − I (1 − β)) (1 − F (x̄∗)) + η (x̄∗; γ)
(1 − βF (x̄∗)) (1 − β). (30)
In general, an optimal solution to the contracting problem (16)-(21) is of the following
form: x̄∗ = x̄∗ (v) , wB (x) = wB (x, v) , yB (x) = yB (x, v) , yAn (x) = yA
n (x, v) , n ≥ 0. Note that
the promised utility is a state variable, which summarizes the history of reports. The contract
dynamics can be described in terms of the evolution of the promised utility. Specifically, suppose
there is no investment before date t and the promised utility level is vt at the beginning of
date t. Then the investment trigger at date t is given by x̄∗ (vt) . If the manager truthfully
reports a high value of cash flows xt ≥ x̄∗ (vt) , then the manager invests and obtains cash
flows yAn (xt, vt) , at the nth period after date t. If the manager truthfully reports a low value of
cash flows xt < x̄∗ (vt) , then the manager does not invest, and obtains compensation yB (xt, vt)
and continuation value wB (xt, vt) . In date t + 1, the starting promised utility level is given by
vt+1 = wB (xt, vt) . The contract then has the same form as that described earlier for date t.
Proposition 3 demonstrates under the CARA utility specification, the above contract form
can be simplified significantly. First, the investment trigger is a constant independent of the
state variable – promised utility. This is similar to Corollary 1 due to the lack of wealth effect.
Second, the compensation yB and continuation utility wB before investment are independent
of cash flows x. Moreover, the dividend dA = x − yA after investment is also independent of x.
We next turn to the discussion of model implications.
4 Model Implications
We first analyze the model’s implication for investment timing. We next turn to the implication
for the dynamics of managerial compensation. After that, we contrast our model with one in
16
which investment is assumed to follow the NPV rule. We finally outline some extensions.
4.1 Investment Timing
Investment timing is determined by equation (25), which characterizes the investment threshold
x̄∗. Its interpretation is similar to that for (9). The left side of (25) is the marginal cost from
waiting (measured in the current period flow payoff). The right side of (25) contains two types
of marginal benefit from waiting. The first term reflects the option value of waiting as in (22).13
Unlike the full information model, risk aversion impacts the option value. From the classical
utility theory, we know that the certainty equivalent η (x̄∗; γ) decreases in risk aversion γ (Mas-
Colell et al. (1995)). Thus, risk aversion lowers the first term on the right side of (25), the
option value of waiting, ceteris paribus. The second term on the right side of (25) is analogous
to the term on the right side of (13). It reflects information rents saved by the owner from
waiting. One can show that this information rents term is positive. These information rents
represent agency costs due to asymmetric information. The owner rationally incorporates both
the option value of waiting and managerial information rents in designing the optimal contract.
Consequently, the optimal investment rule trades off the cost from waiting against the option
value of waiting plus saved agency costs. Importantly, risk aversion affects both components of
the benefit.
As a reference for comparison, we first consider the special case in which the manager is risk
neutral. When γ = 0, the owner does need to take risk sharing motive into account when he
designs the contract. Therefore, even in the presence of asymmetric information, the first-best
efficient investment decision is achieved14. When the manager is risk averse, investment timing
decisions reflect both the owner’s motives to meet the manager’s incentive constraint and to
offer consumption smoothing insurance. We may show that
Proposition 4 (i) Holding investment trigger x̄∗ fixed, the option value β1−β
η (x̄∗; γ) is de-
creasing in γ and the agency cost term
[1 − F (x̄∗) + η′ (x̄∗; γ)] [1 − βF (x̄∗)]
(1 − β) f (x̄∗)(31)
13We call this term the option value component because it vanishes in the static model in (13).14Mathematically, the certainty equivalent η is simply given by η(x̄∗; 0) =
∫ b
x̄(x − x̄) dF (x) and the derivative
of η with respect to the investment trigger is given by η′(x̄∗; 0) = − (1 − F (x̄∗)). Thus, the second term in(25) vanishes and the investment trigger under risk neutrality is the same as the value maximizing trigger underperfect information.
17
is increasing in γ. (ii) If E [x − y|x ≥ y] < 1−βF (y)βf(y) for all y ∈ [a, b] , then there is underinvest-
ment under asymmetric information when risk aversion is high enough; that is, x̄∗ > xFB for
γ large enough.
Part (i) shows that risk aversion has two opposing effects. It lowers the option value of
waiting, thereby speeding up investment. However, it also increases agency costs, thereby
delaying investment. The overall impact of risk aversion and asymmetric information depends
on which effect dominates. Part (ii) demonstrates that when risk aversion is high enough, the
agency cost effect may dominate. This happens when a condition on distribution F is satisfied.
One can verify that this condition is satisfied for exponential and uniform distributions.
For general distributions and risk aversion parameter values, we cannot analytically charac-
terize the effect of risk aversion and asymmetric information on investment timing. We thus turn
to numerical analysis. We choose three specifications for the distribution F : normal distribu-
tion with mean µ and variance σ2, uniform distribution over [0, b], and exponential distribution
F (x) = 1− e−αx over [0,∞). Throughout numerical calculations in this section, we choose the
subjective discount factor β = 0.98 and fix the investment cost at unity (I = 1).
[Insert Figures 2-4 here.]
Figure 2 graphs both the left side and the right side of (25), for a standard normal distri-
bution. The left side (x − (1 − β)I) measures the net benefit from investment. The right side
captures both the option value of waiting and agency costs. We plot the right side of (25) for
various levels of risk aversion coefficient γ. The intersection in Figure 2 gives the investment
trigger. Figure 2 shows that the investment trigger increases with risk aversion coefficient γ.
This is because the agency cost effect dominates the option value of waiting. Similarly, Figures
3 and 4 graph the left side and the right side of (25) for exponential distribution and uniform
distribution, respectively. Both figures also show that investment trigger increases with risk
aversion.
While there are two opposing effects of risk aversion on investment timing, our extensive
numerical exercises show that the agency cost effect dominates the option effect. As a result,
the investment trigger increases in the degree of risk aversion. We next turn to the effects of
volatility on the investment timing decision. Consider normal distribution with mean zero and
18
variance σ2. Figure 5 plots the investment trigger as a function of the volatility parameter σ
and the risk aversion coefficient γ. It reveals that a higher volatility leads to a larger investment
trigger for any value of risk aversion parameter. Moreover, the impact of volatility on investment
is larger for more risk averse managers. This is because our numerical simulations indicate
that both the agency cost component and the option value component increase with volatility,
reinforcing each other and leading to greater incentives to wait. This effect is stronger for more
risk averse managers.
[Insert Figure 5 here.]
4.2 Wage Dynamics
Unlike the static model described in Section 2, in a dynamic setting the owner can choose
an intertemporal incentive scheme to punish or reward the manger such that the managerial
incentives are aligned with the owner. We now describe the wage dynamics implied by the
optimal contract.
Let the initial promised utility to the manager be v0 < 0 in period 0 (the utility function
is negative exponential). According to the optimal contract described in Proposition 3, when
the manager reports truthfully the initial value of cash flows x0 ≥ x̄∗, the manager makes
the investment and hands over x0 to the owner. It follows from (27) that the owner pays the
manager compensation yA0 (x0) = x0 − x̄∗ + yB
0 , which is higher than yB0 , the compensation if
the manager does not invest. Notice that managerial compensation yA0 depends on the project
cash flow x0. The manager who invests in a higher cash-flow project captures more information
rents, ceteris paribus. The owner also promises the manager with a continuation utility value
wA0 (x0) = v0 exp (−γ (x0 − x̄∗ − η (x̄∗; γ))) = wB
0 e−γ(x0−x̄∗) , x0 ≥ x . (32)
It is immediate to note that wA0 is higher than wB
0 . Thus, the owner rewards the manager for
his investment both in terms of current compensation and his future value (via continuation
utility). In period 1, the contract starts with an initial utility level v1 = wA0 . In all periods t ≥ 1,
the owner offers a completely flat consumption profile to the manager in that yAt (x0) = yA
0 (x0) .
When the manager reports truthfully a low value of cash flows in period 0, x0 < x̄∗, the
manger will rationally choose not to make investment according to the optimal contract. The
owner pays the manager a constant compensation in the amount of yB0 = yFB(v0) − η (x̄∗; γ) ,
19
which is lower than yFB(v0), the compensation under full information to yield the manager
with utility level v0. Moreover, to induce the manager to stay in the long-term contract, the
owner also promises the manager a continuation utility given by wB0 = v0 exp (γη (x̄∗; γ)) . Since
the initial utility v0 < 0, it is immediate to see that wB0 < v0. That is, upon a no-investment
decision, the owner punishes the manager by lowering not only his current compensation but
also his continuation utility. In period 1, the contract repeats with the manager’s initial utility
level v1 = wB0 , which is promised by the owner to the manager in period 0. This reflects the
recursive nature of the optimal contract: The promised utility in period 0 is the manager’s
starting utility level at the beginning of period 1.
We next turn to period 1 when there is no investment in period 0. If the manager reports
truthfully a value of cash flows x1 < x∗ in period 1, the optimal contract instructs the manager
not to make investment. By (26), the owner pays the manager
yB1 =
− log (−v1γ (1 − β))
γ−η (x̄∗; γ) =
− log(−wB
0 γ (1 − β))
γ−η (x̄∗; γ) = yB
0 −η (x̄∗; γ) , (33)
which is lower than yB0 . Moreover, the owner promises a continuation value to the manager
wB1 = v1 exp (γη (x̄∗; γ)) = wB
0 exp (γη (x̄∗; γ)) , (34)
which is lower than wB0 . Thus, the owner punishes the manager by lowering both managerial
compensation and continuation utility over time during the period when the manger does not
make investment.
If there is no investment in period 0 and the manager reports truthfully a value of cash
flows x1 ≥ x∗ in period 1, then the optimal contract instructs the manager to make investment.
The owner pays the manager yA1 (x1) = x1 − x̄∗ + yB
1 , and promises him utility
wA1 (x1) = v1 exp (−γ (x1 − x − η (x̄∗; γ))) = wB
0 exp (−γ (x1 − x − η (x̄∗; γ))) . (35)
Thus, the owner gives a current period reward x1 − x̄∗ and promises a higher continuation
utility to the manager if he makes the investment. In all periods t ≥ 2, the owner offers a fat
compensation yAt (x1) = yA
1 (x1) .
While we have extensively discussed the contract dynamics for periods 0 and 1, the pre-
ceding analysis applies for any period. We now summarize the dynamics of compensation and
continuation utility. Let T be the first time at which the manager invests. Then, for all t < T ,
20
no investment is made. By (26) and (28), the compensation and continuation value evolve
according to
yBt = yB
t−1 − η (x̄∗; γ) , wBt = wB
t−1 exp (γη (x̄∗; γ)) , (36)
for all t ≤ T. At time T , xT ≥ x̄∗, the investment is made. By (27) and (29), the compensation
and continuation utility are given by
yAT (xT ) = xT − x̄∗ + yB
T , wAT (xT ) = wB
T exp (−γ (xT − x̄∗ − η (x̄∗; γ))) . (37)
After period T , the manager receives the same level of compensation yAT (xT ) in every period
thereafter. The owner makes a constant stream of profits xT in each period thereafter.
[Insert Figure 6 here]
Now we graph the implied contract dynamics. Figure 6 plots a sample path of dynamic
evolution of managerial compensation and managerial continuation utility, when the underlying
distribution F (x) is uniform on [0,1]. Suppose that xt < x̄∗, for 0 ≤ t ≤ 4 and x5 > x̄∗. Then,
the manager finds optimal to invest in period 5. We have shown that before investment,
compensation decreases by an amount of certainty equivalent η each period and the promised
utility wBt decreases by a factor of (eγη − 1) each period. The left side panel plots the scenario
under which the manager draws a very high cash flow project x5 in period 5. His compensation
yAt after investment (for t ≥ 5) is higher than the full-information compensation level yFB(v0).
The right side panel plots the scenario under which the manager draws a sufficiently high cash
flow project in period 5 to justify his investment decision. However, the cash flow in period
5 is not high enough to give the manager a compensation higher than the full-information
compensation level yFB(v0).
The certainty equivalent η describes how the owner uses the risk averse manager’s con-
sumption smoothing motive to induce managerial truth-telling in an intertemporal setting.
The standard consumer theory tells us that the certainty equivalent for any lottery decreases in
managerial risk aversion.15 Thus, the owner shall offer a flatter consumption path to the more
risk averse manager by decreasing managerial compensation at a slower pace in each period.
Our model also has implications for the dynamics of firm value. Since the owner does not
earn any profits and pays decreasing wages before investment, firm value is increasing over time
15In our model, the lottery offers the payoff max {x − x̄, 0}, for given x̄.
21
before investment. Upon investing, the owner starts to obtain a flat stream of project cash
flows. Thus, firm value jumps to a higher level and remains at the highest level forever.
In our model, commitments in period 0 from both the owner and the manager’s sides are
crucial. Neither side can walk away from the contract after signing it at time 0. The optimal
contract implies that the owner rewards the manager with larger compensation when he invests
in high cash flow projects, and punishes the manager who does not invest by lowering his
compensation over time. One implication of this contract is that a manager who is sufficiently
unlucky for many periods and thus has not invested after many periods will have a decreasing
wage over time. This result to a large extent derives from the manager’s inability to walk away
from the contract, ex post. It is worth generalizing our model to a setting in which the manager
is protected by the limited liability condition. For example, the legal institution may require
that compensation to be higher than certain minimum wage. We leave this extension for future
research.
4.3 Comparison with the NPV rule
We have derived the investment timing decision as part of the optimal contract. One implication
is that information asymmetry delays investment. However, in reality, it is sometimes difficult
to contract on the manager’s investment decisions. To quantify the loss of firm value when
the owner cannot contract with the manager on his investment decision, we need a comparison
model with investment rules specified. The most widely taught investment rule is the NPV rule.
Obviously, the NPV rule in our setting ignores both the option value of waiting and conflicts of
interests between the owner and the manager. However, it seems natural as a benchmark for
our comparison. We now quantify the utility cost of adopting the NPV rule.
According to the NPV rule, investment is made if the cash flow x is larger than the threshold
xm ≡ (1 − β) I. It is straightforward to show that other results of Proposition 3 on compensation
and continuation utility still hold, by replacing the optimal investment threshold x̄∗ with the
trigger rule xm. When the manager chooses the NPV rule over the optimal investment rule,
firm value is lowered since it not optimal.
[Insert Figure 7 here.]
Figure 7 plots the firm value reduction when the NPV rule is adopted. We choose the
22
underlying distribution to be normal with mean 0. The upper and lower graphs plot the value
reduction as a function of coefficient of risk aversion γ, when standard deviation σ = .5 and
σ = 1, respectively. We see that firm value reduction increases with γ. This is because we have
shown earlier that the more risk averse the manager is, the later he invests according to the
optimal contract. Consequently, the simple NPV rule deviates farther away from the optimal
investment rule. Thus, following the NPV rule is more costly to the owner.
4.4 Extensions
We now consider two extension of our model.
Allowing the Manager to Borrow and Save. As in other dynamic principal-agent models,
we have assumed that the owner directly controls the consumption of the manager. That is, the
manager is not allowed to save and borrow at the interest rate R = β−1. However, restricting
the manager from borrowing and lending seems restrictive. We now show that the optimal
contract derived in our model remains optimal after allowing the manager to borrow and lend.
We only need to verify that the manager’s consumption Euler equation is satisfied, in that
u′ (ct) = βREt [u′ (ct+1)] , where Et [·] is the conditional expectation given information available
at period t. This Euler equation after investment is obviously satisfied, because managerial
compensation is constant over time. To show that the preceding Euler equation is also satisfied
before investment, one can use Proposition 3 to verify that16
u′(yB
t
)=
∫ x∗
a
u′(yB
t+1
)dF (xt+1) +
∫ b
x∗
u′(yA
t+1
)dF (xt+1) . (38)
The consumption Euler equation confirms that the dynamic optimal contract described in
Proposition 3 remains optimal, even when the manager can borrow and save.17
16We only need to show that
e−γyB
=
∫ x∗
a
e−γ(yB−η)dF +
∫ b
x∗
e−γ(x−x̄∗+yB−η)dF (x) .
Tis is equivalent to
e−γη = F (x̄∗) +
∫ b
x∗
e−γ(x−x̄∗)dF (x) .
This equation is true by the definition of the certainty equivalent η.17However, in other related settings, the agent may be savings constrained (Rogerson (1985)). That is, if the
agent could save part of the compensation without knowledge of the principal, he would choose to do so. Thatis often reflected in a violation of the Euler equation.
23
Fluctuating Cash flows After Investment. So far, we have assumed that once the man-
ager makes the investment, the value of cash flows is locked in thereafter even though the owner
does not know this value. We now extend our model by considering the scenario under which
the value of cash flows after investment can fluctuate over time. That is, the cash flow in each
period after investment is stochastic and drawn identically and independently from the distri-
bution F . The manager observes the cash flows, but the owner does not. We briefly sketch the
setup. A complete analysis is beyond the scope of the present paper. The key difference between
the problem here and the one analyzed earlier is the contracting problem after investment.
We solve the problem backward. After investment, the optimal contract solves the following
problem18
Π (v) = maxz,w
∫ b
a
[x − z (x) + βΠ (w (x))] dF (x), (39)
subject to
v =
∫ b
a
[u (z (x)) + βw (x)] dF (x), (40)
u (z (x)) + βw (x) ≥ u (z (x̃) + x − x̃) + βw (x̃) , ∀ x̃ . (41)
where (40) is the promise-keeping constraint and (41) is the incentive constraint. We now
consider the optimal contracting problem before investment. It is described by the following
program:
P (v) = max(yB ,wB ,yA,wA,x̄)
∫ x̄
a
[−yB (x) + βP
(wB (x)
)]dF (x) (42)
+
∫ b
x̄
[x − yA (x) − I + βΠ
(wA (x)
)]dF (x)
subject to
v =
∫ x̄
a
[u
(yB (x)
)+ βwB (x)
]dF (x) +
∫ b
x̄
[u
(yA (x)
)+ βwA (x)
]dF (x) (43)
and
u(yA (x)
)+ βwA (x) ≥ u
(yA (x̃) + x − x̃
)+ βwA (x̃) , x, x̃ ≥ x̄, (44)
u(yA (x)
)+ βwA (x) ≥ u
(yB (x̃)
)+ βwB (x̃) , x ≥ x̄ > x̃, (45)
u(yB (x)
)+ βwB (x) ≥ u
(yA (x̃) + x − x̃
)+ βwA (x̃) , x̃ ≥ x̄ > x, (46)
u(yB (x)
)+ βwB (x) ≥ u
(yB (x̃)
)+ βwB (x̃) , x̄ > x, x̃. (47)
18This problem is similar to Thomas and Worrall (1990).
24
Here wA (x) is the continuation value promised by the owner after the manager makes the
investment at reported value x.
5 Conclusion
This paper extends the real options framework to account for informational asymmetry that is
prevalent in many real-world applications. When investment decisions are delegated to man-
agers, contracts must be designed to provide incentives for the manager to reveal his private
information. The owner designs the optimal dynamic contract by both awarding information
rents to the manager and at the same time providing consumption insurance to the manager.
We apply the recursive contract approach to solve this dynamic contracting problem.
We show that compared to the full information benchmark, investment is delayed or there
is underinvestment under asymmetric information. We also show that the optimal contract
punishes the manager over time if he does not make the investment, and rewards him when
he makes the investment. We also show that the option value of waiting decreases with risk
aversion and information rents increases with risk aversion. Moreover, our extensive numerical
simulations indicate that the incentive effect (via information rents) dominates the option effect,
and thus investment is delayed longer when the manager is more risk averse. We also show that
agency costs influence the investment-uncertainty relationship, which has not been emphasized
in the real options literature. In particular, the impact of uncertainty on investment is larger
for more risk averse managers. Finally, we show that the firm value reduction from following
the simple NPV rule increases with managerial risk aversion.
Since our model provides the first recursive analysis of dynamic incentive problems in a
real options model, we aim to highlight the mechanisms by using the simplest possible setting.
This leads us to make some simplifying assumptions. For example, we assume CARA utility.
We also assume that the manager cannot walk away from the contract after signing it at time
0. However, in most employment relationships, the manager has the option to quit his job by
simply forgoing his compensation. Incorporating such limited commitment or limited liability
conditions for the manager makes the owner’s ability to punish the manager for not investing
rather limited.
25
Appendix
A Proofs
Proof of Lemma 1: Since u is increasing, (6) implies that yB(x) ≥ yB(x̃) and yB(x̃) ≥
yB(x) for x, x̃ < x̄. The joint restriction of the two equalities immediately gives a constant
compensation, denoted by yB. Similarly, incentive constraint (3) implies that yA(x) ≥ yA(x̃) +
x − x̃ and yA(x̃) ≥ yA(x) + x̃ − x for x, x̃ ≥ x̄. The joint restriction of the two equalities
immediately gives a constant dividend dA(x̃) = dA(x) = dA, using the definition of dividend
dA(x) = x−yA(x). The incentive constraint (5) implies that yB ≥ yA (x)+x−x. The incentive
constraint (4) implies that yA (x) ≥ yB. Combining these two inequalities and letting x → x,
we obtain yB = yA (x) = x − dA. Q.E.D.
Proof of Proposition 1: We form a Lagrangian as follows:
L = −(x̄ − dA
)F (x̄) +
(dA − I
)(1 − F (x̄)) (A.1)
−λ
[v −
(u
(x̄ − dA
)F (x̄) +
∫ b
x̄
u(x − dA
)dF (x)
)]
= −x̄F (x̄) + dA − I (1 − F (x̄)) − λ
[v −
(u
(x̄ − dA
)F (x̄) +
∫ b
x̄
u(x − dA
)dF (x)
)].
The first-order conditions are
∂L
∂dA= 1 − λ
[u′
(x̄ − dA
)F (x̄) +
∫ b
x̄
u′(x − dA
)dF (x)
]= 0 , (A.2)
∂L
∂x̄= −F (x̄) − (x̄ − I) f (x̄) + λu′
(x̄ − dA
)F (x̄) = 0 . (A.3)
Eliminating the Lagrangian multiplier gives the formula reported in Proposition 1. Q.E.D.
Proof of Corollary 1: It is straightforward to derive it from Proposition 1. It is also a
special case of Proposition 3 when β = 0. Q.E.D.
Proof of Proposition 2: We conjecture that the value function P (v) takes the following
form
P (v) = −u−1 ((1 − β) v)
1 − β+ H, (A.4)
26
where H is a constant to be determined. Substituting it into (16) and using the Lagrange
method, one can derive the desired result and
H =
∫ b
xFB (x − (1 − β) I) dF (x)
(1 − β) [1 − βF (xFB)]. (A.5)
We next show that xFB is the same as the investment trigger for a risk neutral investor. To
this end, let V (x) be the value function of the risk neutral investor. Then V (x) satisfies the
Bellman equation
V (x) = max
{x
1 − β− I, β
∫V
(x′
)dF
(x′
)}. (A.6)
Since V (x) is increasing, there is a trigger value x∗ such that when x < x∗, there is no invest-
ment, and when x ≥ x∗, investment is undertaken. That is
V (x) =
{x
1−β− I if x ≥ x∗,
β∫ b
aV (x′) dF (x′) if x < x∗.
(A.7)
By continuity of V (x) at the threshold value x∗, we have
x∗
1 − β− I = β
∫ b
a
V(x′
)dF
(x′
)= β
∫ x∗
a
V(x′
)dF
(x′
)+ β
∫ b
x∗
V(x′
)dF
(x′
)(A.8)
= β
∫ x∗
a
(x∗
1 − β− I
)dF
(x′
)+ β
∫ b
x∗
(x′
1 − β− I
)dF
(x′
).
Subtracting β∫ b
x∗
(x∗
1−β− I
)dF (x′) on each side of the above equation and simplifying yield
(22). To prove the existence of uniqueness, we use the fact that the left-side of (22) is an
increasing function of x∗ and the right-side of (22) is a decreasing function of x∗. Using the
assumption I ∈ (a/ (1 − β) , b/ (1 − β)) , we apply the intermediate value theorem to obtain the
desired result. Q.E.D.
Proof of Lemma 2: (i) The incentive constraint (21) implies that u(yB (x)
)+ βwB (x) is
constant for all x < x̄. The incentive constraint (20) implies that
u(yB (x)
)+ βwB (x) ≥
∞∑
n=0
βnu(yA
n (x̄) + x − x̄). (A.9)
But (19) implies that∞∑
n=0
βnu(yA
n (x̄))≥ u
(yB (x)
)+ βwB (x) . (A.10)
27
Combining the above two inequalities and letting x → x, it follows from the continuity of u
that u(yB (x)
)+ βwB (x) is continuous at x̄ and equal to the value at x̄ for all x < x̄. Thus,
we obtain (24).
We now show that given (18), condition (24) implies (19)-(21). First, (21) is trivially true.
Use (18) and (24) to deduce
u(yB (x)
)+ βwB (x) =
∞∑
n=0
βnu(yA
n (x̄))≥
∞∑
n=0
βnu(yA
n (x̃) + x − x̃)
(A.11)
≥∞∑
n=0
βnu(yA
n (x̃) + x − x̃)
for all x̃ ≥ x > x,
which gives (20). Finally, use (18) and (24) to deduce
∞∑
n=0
βnu(yA
n (x))
≥∞∑
n=0
βnu(yA
n (x̄) + x − x̄)≥
∞∑
n=0
βnu(yA
n (x̄))
(A.12)
= u(yB (x)
)+ βwB (x) for all x ≥ x > x̃,
which gives (19).
(ii) Substitute dAn (x) = x − yA
n (x) into (18). By the CARA utility specification, x can be
cancelled out from (18). We can then deduce that∑∞
n=0 βn −eγdn(x)
γis independent of x. Denote
this constant value by W. We can rewrite the contract problem (16)-(21) as
P (v) = maxy,z,w,x̄
∫ x̄
a
[−yB (x) + βP
(wB (x)
)]dF (x) +
∫ b
x̄
[∞∑
n=0
dAn (x) − I
]dF (x) (A.13)
subject to
v =
∫ x̄
a
[u
(yB (x)
)+ βwB (x)
]dF (x) + W
∫ b
x̄
e−γxdF (x) , (A.14)
u(yB (x)
)+ βwB (x) = We−γx̄, x < x̄, (A.15)
W =∞∑
n=0
βn−eγdAn (x)
γfor all x ≥ x̄. (A.16)
If P (·) is differentiable and strictly concave, one can use the Lagrange method to show that
dAn (x) is independent of x and n, and that yB (x) and wB (x) are independent of x for x < x.
Q.E.D.
28
Proof of Proposition 3: (i) We conjecture that the value function P takes the following
form
P (v) =log (−v)
γ (1 − β)+ K, (A.17)
where K is a constant to be determined.19 We use Lemma 2 to simplify the optimal contracting
problem as
P (v) = maxyB ,dA,wB ,x̄
[−yB + βP
(wB
)]F (x̄) +
(dA
1 − β− I
)(1 − F (x̄)) (A.18)
subject to
v =
[−e−γyB
γ+ βwB
]F (x̄) +
∫ b
x̄
−e−γ(x−dA)
γ (1 − β)dF (x) , (A.19)
−e−γyB
γ+ βwB =
−e−γ(x̄−dA)
γ (1 − β). (A.20)
Substitute (A.17) into (A.18) and use the first-order conditions for yB and wB to obtain
wB =−e−γyB
γ (1 − β). (A.21)
Substituting this expression into (A.20) to solve for dA, we obtain
dA = x̄ − yB. (A.22)
Substituting (A.17), (A.21) and (A.22) into (A.18) and (A.19), we can simplify the problem to
P (v) = maxyB ,x̄
[−
yB
1 − β−
β log [γ (1 − β)]
γ (1 − β)+ βK
]F (x̄) +
(x̄ − yB
1 − β− I
)(1 − F (x̄)) (A.23)
subject to
v =−e−γyB
γ (1 − β)
[F (x̄) +
∫ b
x̄
e−γ(x−x̄)dF (x)
]. (A.24)
We use (A.24) to solve for yB to obtain
yB =− log (−v)
γ+
− log γ (1 − β)
γ+
1
γlog
{F (x̄) +
∫ b
x̄
e−γ(x−x̄)dF (x)
}. (A.25)
Substitute this expression into the right-side of (A.23) and use the definition (12) to obtain
P (v) = maxx̄
log (−v)
γ (1 − β)+
log (γ (1 − β))
γ (1 − β)+
η (x̄; γ)
1 − β(A.26)
+
[−
β log [γ (1 − β)]
γ (1 − β)+ βK
]F (x̄) +
(x̄
1 − β− I
)(1 − F (x̄)) .
19By a standard dynamic programming argument (e.g., Thomas and Worrall (1990)), one can show that thereis a unique value function P (·) solving the contract problem.
29
This verifies our conjectured functional form of P (v) in (A.17). Moreover, matching equations
(A.26) and (A.17) gives an equation for K,
K = maxx̄
log (γ (1 − β))
γ (1 − β)+
η (x̄; γ)
1 − β(A.27)
+
[−β log [γ (1 − β)]
γ (1 − β)+ βK
]F (x̄) +
x̄ − (1 − β) I
1 − β(1 − F (x̄)) .
By the first-order condition for (A.26), we have
η′ (x̄; γ)
1 − β+
[−β log [γ (1 − β)]
γ (1 − β)+ βK
]f (x̄) +
1 − F (x̄)
1 − β−
x̄ − (1 − β) I
1 − βf (x̄) = 0 (A.28)
Evaluated at the optimum, equation (A.27) implies that
K =log [γ (1 − β)]
γ (1 − β)+
(x̄ − I (1 − β)) (1 − F (x̄)) + η (x̄; γ)
(1 − βF (x̄)) (1 − β). (A.29)
Substitute this expression into the preceding first-order condition to obtain that the optimal
trigger satisfies
x̄ = (1 − β) I +1 − F (x̄) + η′ (x̄; γ)
f (x̄)+
β (x̄ − I (1 − β)) (1 − F (x̄)) + βη (x̄; γ)
1 − βF (x̄). (A.30)
Multiplying 1 − βF (x̄) on each side and simplifying yield (25).
We next check the second-order condition for an optimum is satisfied. Taking a second-order
derivative in (A.26) gives
η′′ (x̄; γ)
1 − β+
[−β log [γ (1 − β)]
γ (1 − β)+ βK
]f ′ (x̄) −
2f (x̄)
1 − β−
x̄ − (1 − β) I
1 − βf ′ (x̄) . (A.31)
We will show that this expression is negative at x̄∗. We first substitute the preceding expression
for K into it and multiply (1 − β) to obtain
η′′ (x̄∗; γ) − 2f (x̄∗) +βf ′ (x̄∗) η (x̄∗; γ)
1 − βF (x∗)− [x̄∗ − (1 − β) I]
f ′ (x̄∗) (1 − β)
1 − βF (x∗). (A.32)
We now use equation (25) to substitute [x̄∗ − (1 − β) I] . Simplifying the resulting expression
yields
η′′ (x̄∗; γ) − 2f (x̄∗) −f ′ (x̄∗) (1 − F (x∗) + η′ (x̄∗; γ))
f (x̄∗). (A.33)
It suffice to show that this expression is negative. In fact, by the assumption that
1 − F (x) + η′ (x; γ)
f (x)(A.34)
30
is decreasing in x, we differentiate this expression to derive
f ′ (x̄∗) (1 − F (x∗) + η′ (x̄∗; γ))
f (x̄∗)> η′′ (x̄∗; γ) − f (x̄∗) . (A.35)
This inequality delivers our desired result.
We finally show that the existence and uniqueness of the solution to (25). Since η (x; γ) is
decreasing in x, it follows from the assumption that the right side of (25) is decreasing in x̄∗.
One can also check the right side is equal to zero when x̄∗ = b and is positive when x̄∗ = a. The
desired result follows from the intermediate value theorem.
(ii) Equation (26) follows from (A.25) and the definition of η. Since yB = x−dA, (27) follows
from (A.22).
(iii) Equation (28) follows from (A.21) and part (ii). Equation (29) follows from Lemma 3
and (A.22).
(iv) It follows from (A.17) and (A.27). Q.E.D.
Proof of Proposition 4: (i) First, η (x̄; γ) is decreasing in γ by Mas-Colell et al. (1995).
Moreover, one can check that
η′ (x̄, γ) =−
∫ b
x̄e−γ(x−x̄)dF (x)
F (x̄) +∫ b
x̄e−γ(x−x̄)dF (x)
(A.36)
is increasing in γ.
(ii) When γ → ∞, η (x̄; γ) → 0 and η′ (x̄, γ) → 0, and thus the investment trigger satisfies
x̄∗ − (1 − β) I =[1 − F (x̄∗)] [1 − βF (x̄∗)]
(1 − β) f (x̄∗). (A.37)
When γ = 0, the investment trigger xFB satisfies (22). If the condition in the proposition is
satisfied, then the expression on the right side of the preceding equation is larger than that
on the right side of equation (22), when x̄∗ and xFB are replaced with y. This implies that
x̄∗ > xFB for γ = ∞. By continuity, this is also true for γ large enough. Q.E.D.
31
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34
00.5
0.55
0.6
0.65
0.7
0.75
1 7 92 843 5 6 10
risk aversion
Inves
tmen
tth
resh
old
Figure 1: Investment threshold and risk aversion in the static setting. Thisfigure plots the investment threshold at varying levels of risk aversion for CRRA utility(u(c) = c1−γ/ (1 − γ)
)and uniform distribution over [0, 1]. Set parameter value I = 0.5 and
reservation utility v = 0.11−γ/(1 − γ).
35
2
20
4
6
the value of x
x − (1 − β)I
γ = 0
γ = ∞
Figure 2: Investment threshold and risk aversion in the optimal dynamic contract.Utility is CARA (u(c) = −e−γc/γ) and F is the standard normal. Set β = 0.98 and I = 1.From the lowest to the highest graphs, the manager’s coefficient γ of risk aversion is 0 (riskneutral), 1, 5, and ∞, respectively.
36
1
10.75 0.85 0.950.8 0.9
0.5
1.5
2.5
3.5
2
0
3
the value of x
Figure 3: Investment threshold and risk aversion in the optimal dynamic contract.Utility is CARA (u(c) = −e−γc/γ) and F is the uniform distribution over [0, 1]. Set β = 0.98and I = 1. From the lowest to the highest graphs, the risk aversion parameter γ is 0 (riskneutral), 1, 5, and ∞, respectively.
37
4.5 5.5 6.552
4
4
6
6
8
10
12
14
16
7
the value of x
Figure 4: Investment threshold and risk aversion in the optimal dynamic contract.Utility is CARA (u(c) = −e−γc/γ) and F is an exponential distribution over [0,∞). Set β = 0.98and I = 1. From the lowest to the highest graphs, the risk aversion parameter γ is 0 (riskneutral), 1, 5, and ∞, respectively.
38
1
1
1
3
1.5
1.5
1.5
2.5
0.5
0.50.5
3.5
Inves
tmen
tth
resh
old
γσ
2
2
2
0
0 0
Figure 5: Investment Threshold, volatility, and risk aversion. This figure plots invest-ment threshold as a function of volatility and risk aversion parameters for normal distributionswith mean zero and variance σ2. Utility is CARA (u(c) = −e−γc/γ). Set β = 0.98 and I = 1.
39
-3-3
-4-4
-2.5-2.5
-3.5-3.5
0.50.5
0.520.52
0.540.54
0.560.56
0.580.58
0.60.6
22
22
44
44
66
66
88
88
1010
1010
00
00
manager
ialutility
com
pen
sation
Figure 6: The dynamics of managerial compensation, and continuation utility. Thetwo graphs on the left (right) panel plot the dynamics for a high (low) value of cash flows uponinvestment. Utility is CARA (u(c) = −e−γc/γ) and F is the uniform distribution over [0, 1].Set β = 0.98 and I = 1.
40
1
1
35
45
55
50
3
3
2
2
40
17
18
19
20
21
22
23
0
0
σ = .5
σ = 1
firm
valu
ere
duct
ion
∆P
firm
valu
ere
duct
ion
∆P
risk aversion
risk aversion
Figure 7: Firm value reduction from using the NPV rule. Utility is CARA(u(c) = −e−γc/γ) and F is a normal distribution with mean zero. Set β = 0.98 and I = 1.
41