Matching Estimation, Casino Gambling and the …rate of growth of consumer spending on casino...
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Matching Estimation, Casino Gambling and the Quality of Life
Michael Wenz
Department of Economics and Finance Winona State University
310 Somsen Hall Winona, MN 55987 [email protected]
507-452-5698 Abstract: Little consensus exists in the literature as to the impact of casino gambling on regional economic development. This paper uses a propensity score matching estimator to assess the bottom line impact of casino gambling on the welfare of local residents. It extends the literature in two important ways. First, the traditional matching estimation model is extended to consider a kernel weighting formula that corrects for correlation between the outcome error term and characteristics of the regressors used in generating the propensity scores. Second, by using the matching procedure to control for selection bias in the casino location decision, this paper generates improved estimates for the impact of casino gambling on key economic variables and on local quality of life. Casinos are found to have no statistically significant net impact on the quality of life in their host counties, though Native American casinos do generate some additional economic activity in the form of increased population, employment, and housing starts. JEL Codes: O12, R1, R13, R58 I gratefully acknowledge support from the U.S. Department of Housing and Urban Development Doctoral Dissertation Research Grant Program. This paper was prepared during my time as a graduate student at University of Illinois at Chicago. I am thankful also for helpful comments from Dan McMillen, Barry Chiswick, Joe Persky, Gib Bassett, John Tauras and Josh Linn. Any errors are my own.
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Introduction
A primary challenge in assessing the economic impact of an event or a policy is the
construction of a counterfactual for identifying whether the outcome would have occurred but for
the event. The construction of an appropriate counterfactual is essential if one hopes to attribute
causation to the event. One method of developing a counterfactual is by using propensity score
matching. This method will be applied here to the case of casino gambling.
Little consensus exists in the literature as to the bottom line social welfare impact
associated with casino gambling1. The nonrandom nature of site selection by governments and
casino operators suggests that simply comparing outcomes across the treated (casino) group and
the nontreated (non-casino) control group of regions will suffer from selection bias. Propensity
score matching involves pairing each observation in the treatment group with a matched
observation constructed from the control group in a way that eliminates selection bias, and
comparing the difference in outcomes between the two groups. The traditional matching
estimator will be extended to consider bias introduced by correlations between observed
characteristics used in the propensity score model and measured outcomes. It will be used to
assess the impact of casinos on key economic variables, and to relate these measures to welfare
and quality of life.
Casinos may have a positive impact on the quality of life by increasing economic profits,
tax revenues, or consumer surplus, and may negatively impact quality of life by creating
externalities through increased incidence of problem or pathological gambling. Prior research
suggests that casinos are associated with increases in economic activity (Evans and Topoleski
2002) and increases in crime (Grinols and Mustard, 2006), but previous work has struggled to 1 See, for example, Grinols and Mustard (2001), Walker and Barnett (1999), Walker (2003).
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assess the bottom line impact of casinos on communities. This study applies a hedonic pricing
model using data from the 1990 and 2000 census to calculate the implicit willingness to pay to
live near a casino. The key results indicate that on net, casinos neither raise nor lower the quality
of life in their host county, though Native American casinos do generate increased economic
activity as measured by employment, housing starts, and population. These results are robust to
a number of different specifications of the matching estimator.
This paper begins with a brief history of casino gambling in the United States. The
second section extends the quality of life model developed by Roback (1982) to consider casino
gambling. The third section discusses matching estimation. The fourth section discusses the
data used in constructing the propensity score and the matched outcomes. The fifth section
presents the results of the model under a number of different specifications and extends the
matching estimator to correct for a specific form of potential bias. The final section concludes.
A brief history of casino gambling
In 1988, Congress passed the Indian Gaming Regulatory Act (IGRA), which explicitly
outlined the terms of legalized gambling on reservations. This act followed a series of
contentious legal battles between states and Indian reservations surrounding tribal attempts to
open casinos and high-stakes bingo parlors. The IGRA removed much of the uncertainty
surrounding the legality of casino gambling, and marked the beginning of a widespread
expansion of gambling on both Native American and on non-Native American lands. By 2000,
29 states were home to casino-style gambling.
Though gambling has long been legal in 48 states, mostly in the form of state-sponsored
lotteries, casino-style gambling has largely been prohibited. In 1976, Atlantic City, NJ joined the
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state of Nevada as the second jurisdiction in the United States with legalized casino-style
gambling. Around this time, a handful of Native American tribes operated high-stakes bingo
parlors, notably the Penobscot Tribe of Maine, which opened a high-stakes bingo parlor in 1973,
and the Seminoles of Florida, which opened a high-stakes bingo parlor in 1978. These
establishments met with resistance from state governments, who filed several lawsuits attempting
to put an end to gambling on reservations. Most importantly, the case of California v. Cabazon
and Morongo Bands of Mission Indians went to the U. S. Supreme Court, which ruled in 1987
that if states allow a particular form of gambling within the state, they have no ability to regulate
that form of gambling on tribal lands.
It was in response to this decision that congress passed the IGRA (Evans and Topoleski
2002). The IGRA identifies three classes of gaming:
Class I: Social games for prizes of minimal value and traditional forms of Indian gaming
engaged in as part of tribal ceremonies or celebrations.
Class II: Bingo and games similar to it such as pull-tabs, tip jars, and certain non-
banking card games.
Class III: All other forms of gaming including banking card games, slot machines, craps,
parimutuel horse racing, dog racing, and lotteries. Casinos fall into this category.
Class I games are subject only to tribal regulation; Class II games are subject to tribal regulation
and oversight from the National Indian Gaming Commission (NIGC), and Class III games are
legal only if approved by the NIGC and agreed upon by a tribal-state compact. A tribal-state
compact can only permit Class III gaming of forms which are legal in some form in the state,
though the courts have given this a very loose interpretation. For instance, Connecticut allowed
non-profit organizations to host “Casino Nights” as fund raisers, and the Mashantucket Pequots
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successfully used this as legal support for their efforts to open the largest casino in the world
(Evans and Topoleski 2002). Compacts generally restrict the size and scope of gaming
operations, as well as the types of gaming devices and games available. In some cases, they
include a payment to the state, often in exchange for the right to be the exclusive provider of
casino gambling.
Passage of the IGRA triggered rapid expansion of casino gambling, not just on Native
American lands, but all across the United States. Iowa legalized riverboat gambling in 1989, and
opened their first riverboat casino in 1991. In November of 1989, the mining town of
Deadwood, SD became the first place outside of Atlantic City and Nevada to open a non-Native
American casino. Gambling in Deadwood and in three mining towns in Colorado was limited to
historic buildings and placed strict limits on the size of a wager. In Deadwood, for instance, the
maximum wager is $100. Riverboat casinos were legalized in Illinois, Mississippi, Louisiana,
Missouri, and Indiana between 1990 and 19932, and New Orleans (1992) and Detroit (1996)
authorized land-based casinos as well. Outside Nevada, by 2000, there were 358 Class III style
casinos operating in 28 states. Of these, 176 were Native American and 182 were non-Native
American. A map of casino locations as of 2000 is displayed in Figure 1. By 2000, 189
counties had at least one operating casino, either Native American or non-Native American.
The rate of growth in casino locations has slowed, but expansion continues to be an
important political topic in many states, including Illinois, Minnesota, and Kentucky. Even as
the growth in the number of casinos has slowed, the number of gaming stations at each location
continues to increase, and casino-style gambling is expanding into race tracks. Additionally, the
2 Riverboats and cruising requirements appear to have been used in an attempt to protect customers from excessive gambling by using time constraints to limit their maximum loss on a particular excursion. Over time, cruising requirements have been relaxed or eliminated, and riverboats bear little practical distinction from land-based casinos. See Eadington (1999).
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rate of growth of consumer spending on casino gambling remains high, growing from $16 billion
in 1995 to $24.5 billion in 2000, to $30.3 billion in 2005 (American Gaming Association 2006).
Understanding the economic impact of casino gambling remains an important issue.
Quality of life modeling and casinos
The primary goal of this paper is to obtain an estimate of the net benefit (or cost) of a
casino to its home region. As an alternative to the cost-benefit analysis used in previous
research, a hedonic quality of life model is used to infer the valuation of living in an area with a
casino. (1974) shows that a differentiated good can be expressed as a vector of its
characteristics. The price of good i depends on the marginal valuation of the good’s
characteristics:
Pi = P(s1, s2, …, sn) (1)
and δP/δsj represents the marginal implicit price of characteristic j. In the case of a house, the
characteristics may include, for instance, the physical features of the house, the level of local
public services and taxes, the risk of crime, and the weather. In particular, the social costs and
benefits associated with living near a casino will be characteristics that influence house prices,
and will have a corresponding implicit price.
Housing represents a differentiated good, and the implicit prices of its characteristics can
be determined in the method outlined by Rosen3. House prices differ across space, based on the
different quantities of characteristics available at each location. However, utility levels are
3 The use of hedonic models to value environmental amenities has a long history in the literature. See, for example, Palmquist (1984) and Greenstone and Chay (2005).
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assumed to be constant across space. The implicit price of the social costs and benefits of a
casino is given by the equilibrium differential that allocates individuals among locations so that
utility levels across space are equal. If casinos provide a net benefit to nearby individuals, they
should be willing to pay higher house prices; otherwise, people could increase their utility by
moving to the region, placing upward pressure on land values and house prices in the region.
This differential represents the marginal willingness to pay for the bundle of amenities associated
with a casino.
Suppose that the amount of some characteristics (j, k,…) which enter into the hedonic
price function depend on the presence of a casino. Then the price of house i is
Pi = P(s1, s2, … sj(C), sk(C),…) (2)
and
δPi/δC = Σj (δPi/δsj)(δsj/δC) (3)
For illustrative purposes, let sj represent the amount of crime. Then term j represents the
increase in the level of crime associated with the casino times the implicit price of an incremental
increase in crime. In other words, it is the marginal willingness to pay to avoid the increase in
crime caused by the casino. To the extent that casinos impact other characteristics that influence
utility, their marginal impact is expressed in other terms in equation (3). Roback (1982) extends
the model to include the labor market, noting that both housing prices and wages work to
allocate people across space. The full implicit price of the amenity bundle, then, includes a term
for the impact of casinos on house prices and a term for the impact of casinos on wages.
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Blomquist et. al. (1988) explicitly account for the fact that housing is produced using both land
and housing materials, so the full implicit price of the amenity bundle becomes
δPi/δC = H(dr/ds) – (dw/ds) (4)
where H represents the quantity of housing consumed, r represents land rent, w represents the
wage rate, and s is the vector of amenities influenced by the casino.
The advantage of the hedonic approach compared to traditional cost-benefit studies is that
it does not require the identification and measurement of an itemized list of costs and benefits.
Traditional cost-benefit analysis requires a measure of each term in equation (3) to compute an
estimate of costs and benefits, but the hedonic approach only requires the calculation of the
change in house prices and the change in wages, both of which are observable.
One difficulty with using a hedonic price function to estimate the implicit price of an
amenity such as casino gambling is the potential presence of unobserved characteristics that are
correlated with both the level of the amenity and housing prices. In particular, the casino
location decision is likely to be endogenous, and to the extent that the decision by communities
to supply casino gambling is influenced by unobservables which also affect house prices, the
hedonic estimates may be biased. The matching estimator employed here is designed to control
for this source of bias.
Matching as an empirical estimation strategy
The estimation strategy employed here will use a difference-in-differences approach in
the construction of a propensity score matching estimator. The goal is to identify the change in
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quality of life due to the presence of a casino, which requires an estimate of the change in wages
and house prices in two states of the world, one with a casino (state 1) and one without (state 0).
The impact of the casino on a particular outcome is given by Yt,1 – Yt,0, where Yt,1 is the outcome
which would exist at time t in the presence of a casino, and Yt,0 is the outcome which would
prevail at time t without a casino. This second term is inherently unknowable, since at time t,
only one of the states is possible. One possible solution would be to compare the difference in
mean outcomes of each group, the casino group and the non-casino group, but this is problematic
for reasons outlined below.
The propensity score matching method was developed to address the problem of
measuring the true effect of a treatment on the treated when selection into the treatment group is
not random, but depends on the characteristics of the subject. For example, suppose two students
ask for extra assistance in preparation for an exam, but the teacher has time to help only one.
Suppose further that both students received a B on the exam. We might conclude that the extra
assistance did not help. If, however, we knew that the student who received help was selected to
receive help because their prior performance was C-level, compared to the B-level performance
of the student who was not selected, then we might conclude that in fact the extra assistance did
help. Propensity score matching provides a way to compare the outcomes of subjects with
similar probabilities of being selected into the treatment group—that is, to compare the
differences in outcomes of previously C-level students who received assistance with the
outcomes of other C-students who did not receive assistance. In the case of casino gambling, the
concern is that casinos endogenously locate in places which are good candidates for growth
otherwise, and that comparing them to a random sample of other places will yield a biased
estimate of the impact of casinos on local quality of life.
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Construction of a difference-in-differences matching estimator is a two-step process
requiring repeated cross-sectional data on both casino locations and non-casino locations. The
first step in applying the estimator involves the construction of a propensity score based on the
determinants of selection into the treatment group. A parametric procedure such as logit
estimation is used to construct a propensity score for each observation, where the propensity
score represents the probability that an observation is selected into the treatment group.
Rosenbaum and Rubin (1983) show that under certain assumptions discussed below,
observations in the non-treatment group can be selected to provide an unbiased counterfactual to
use for comparisions. In the second step, observations in the treatment group are matched with
observations in the non-treatment group, and the difference in mean outcomes is computed.
Several methods have been proposed for matching observations, including the simple average
nearest neighbor estimator and the kernel regression matching estimator (Todd 1999). The
nearest neighbor method simply chooses one or a small number of observations that are closest
in propensity score to each member of the treatment group. These observations form the
comparison group, and the difference between the outcome of treated observation and the
average outcome of the comparison observations is the observed effect of the treatment. A
kernel regression estimator assigns different weights to each nearby non-treated observation
based on their distance from the treatment observation. This requires choosing a bandwidth from
which to choose the observations. In either case, the sensitivity of results to the choice of the
number of nearby observations or the appropriate bandwidth to use should be examined.
In choosing the model parameters to be used in constructing the propensity score, it is
important to be sure that these values are not influenced by the treatment (Heckman et. al., 1998,
Todd 1999). Using only the pre-treatment values for the variables in the construction of the
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propensity score gives some confidence that the values have not been influenced by the
treatment4.
The outcome measures of interest are the mean change in house prices and the mean
change in earnings in matched pairs of casino and non-casino counties. A difference-in-
differences matching estimator assumes:
E(Yt,0 – Yt-1,0 | P(X), C=1) = E(Yt,0 – Yt-1,0 | P(X), C=0) (5)
and
0 < Pr (C=1| X) <1 (6)
where Yt,0 represents the outcome of an observation at time t who did not receive the treatment,
X is a vector of characteristics which influence selection, P(X) is the propensity score, and C is a
dummy variable indicating whether the observation received the treatment (a casino) or not
(Rosenbaum and Rubin 1983, Todd 1999). In other words, equation (8) says the expectation for
the outcome of a non-treated observation, conditional on P(X), is the same as the expectation for
a treated outcome conditional on P(X), had the treated subject not received the treatment. The
left-hand side of equation (8) is unobservable, though this is the desired comparison group. The
right-hand side of equation (8) is observable and provides the necessary counterfactual to
measure the effect of the treatment. This underscores the importance of the propensity score,
which is being relied upon to identify the suitability of comparisons. Heckman et. al.(1998)
demonstrate that with selection based on observed characteristics, estimation of the effect of
treatment on the treated does not depend on the choice of functional form or the distribution of
unobservables. The second step in the estimating process is thus reduced to a one-dimensional,
non-parametric estimation problem. The key assumption required comes in the first step in the
4 It is possible that house prices and wages move in anticipation of the opening of the casino, and that announcement dates would be more appropriate than opening dates. This would affect only a few observations in this study.
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process, the assumption that the creation of the propensity score sufficiently captures the factors
which influence selection into the treatment group or the non-treatment group.
Equation (9) indicates that matching will not work for values of X that guarantee
selection with certainty into either the treatment group or the control group. This requires
investigation for regions of common support, where a value for X includes both observations
selected for treatment and observations which are not. It is unlikely that each observation in the
treatment group will share an identical set of X characteristics with an observation in the control
group, so this issue in practice reduces down to finding observations in one group that are nearby
in terms of propensity score distance to observations in the other group. Matching can lead to
some unintuitive pairs of observations. Suppose for instance that one county is very likely to
have a casino because it has a high concentration of Native Americans, while another is likely to
have a casino mostly because it has a low concentration of fundamentalist Christians. This can
lead to the matching of counties that are not necessarily similar to each other. It should be noted
that the matching estimator does not directly seek to match similar counties, but to create a
control distribution that closely resembles the treatment distribution. In essence, matching takes
a nonrandom experiment and randomizes it. The matching method is more appropriate when, for
each observation in the treatment group, there are many similar observations that did not receive
the treatment. Aside from the issue of overlapping support, a lack of potential comparison
observations in a propensity score range can lead to some observations being selected as
comparisons multiple times. This can lead to giving very large weight to a few observations.
These issues will be discussed below as they relate to the data used in this study.
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Data
The construction of a matching estimator takes place in two steps. First, a propensity
score model assigns predicted probabilities of receiving the treatment to each observation, and
second, the treatment observations are matched with control observations to assess the impact of
the treatment. The difference-in-differences matching estimator can be employed with repeated
cross-sectional data. The data used here is from the 1990 and 2000 U.S. Census of Population.
The unit of observation is the county
The propensity score model used here is drawn directly from Wenz (2006, Table X, p.
58-59). The likelihood that a county will open a casino is linked to a number of factors,
including population, local attitudes toward gambling, characteristics of neighboring
communities, and the region of the country. A logit model constructed predicted probabilities
for the presence of a casino in each county. The model parameters are shown in Table 1, and
data definitions and sources are provided in Table 2.
Some interesting results from the propensity score model are presented in Table 3. Note
that Cook County, IL is the second-most likely county to open a casino among those that have
not. For at least the past six years, efforts to bring a casino to Cook County have been in the
works and are currently tied up in the courts. Aside from Starr County, TX, the rest are in states
with a heavy gaming presence. Starr County is generally an anomaly. Much of their propensity
score owes to a 40.8% unemployment rate, the highest recorded in the dataset. Of the counties
that have casinos despite low propensity scores, the general tendency is for them to be located in
states without much gaming, and far away from the population center of the state. Oneida, NY is
far away from New York City, for instance, and Swain County, NC is in a remote area at the
foothills of Smoky Mountain National Park in far western North Carolina. Table 4 outlines the
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distribution of propensity scores across casino and non-casino counties. There is overlapping
support in all areas of the data, though it is much thinner when predicted probabilities are above
60%.
The variables needed for the quality of life analysis are the change in the county median
house price and the change in the county median income between the 1990 and 2000 Censuses.
The house price measure in the census is the respondent’s estimated house value, and the median
level is reported for each county. The income measure is the median income in 1989 and 1999
for households in the county. Other economic outcomes include the change in median rents, the
change in population, employment and housing units, and the number of new housing units
constructed.
As noted above, the possibility of feedback between the explanatory variables and the
treatment needs to be considered. One advantage of using a difference-in-differences approach
is the ability to use observed explanatory variables before the treatment. That is, the measures
that go into the construction of the propensity score can be viewed at pre-treatment levels. In the
propensity score model applied here, a few difficulties arise. First, it is difficult to pinpoint the
opening dates of Native American casinos. Some existed prior to passage of the IGRA, and
some existed as Class II gaming facilities before becoming casinos, and there is no readily
apparent way to verify the opening dates of casinos with certainty. What is known is that no
gaming compacts were signed prior to 1990, that there were only a small number of Native
casinos prior to 1990, and that the first non-Native casinos outside of Nevada and Atlantic City
opened in November of 1989 in Deadwood, SD. The estimation method used here treats all of
the counties in the dataset as if there were no casino in the county as of 1990. This approach
assumes that for the small number of casinos open prior to the taking of the 1990 census, the
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casino did not impact the levels of the explanatory variables. It also assumes that variables do
not move in anticipation of a casino opening. This is not a problem for things like whether the
county is on a river, but casinos may possibly affect things like the unemployment rate and may
even affect things like the proportion of fundamentalist Christians in a region, though changes in
the religious makeup or voter attitudes in a region are likely to be very slow and not change
much in a year or two. With respect to the quality of life estimates, another concern is that house
prices move in anticipation of the opening of a casino, though it is difficult to imagine that in
early 1990 when the census was taken that residents had much information about how casinos
would affect house prices. In any case, it is likely that less than 10 of the 188 casino counties
would see any influence of the casino in either their explanatory variables or their outcome
variables.
Econometric Specification
A number of different ways of applying the matching estimator will be presented based
on this specification of the propensity score model from Wenz (2006) described above. The first
approach is to estimate this model on the full sample of counties and on three other subsamples,
and to create a one-to-one nearest neighbor match for each of the subsamples. The second
approach is to estimate the full model on the full sample of counties and to construct a distance-
weighted match for all of the observations within a bandwidth of 0.05. The third approach uses a
distance-weighted nearest neighbor method that fixes the number of observations to be used in
the comparison group, rather than the bandwidth. Finally, the model is estimated on the full
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sample of counties with using a bandwidth of 0.10, but constraining the comparison observations
to come from the same census region and from similarly sized counties.
Single Nearest Neighbor Matching
The logit model developed in the preceeding chapter was used to construct propensity
scores for the full sample of counties. A simple one-to-one nearest neighbor match selected one
county from the treatment (casino) group and one from the control (non-casino) group. In most
instances, the control group match was simply the non-casino county with the propensity score
nearest to the propensity score of the casino county. One problem that arises from this approach
is that some control counties are the nearest neighbor to multiple treatment counties and would
thus receive disproportionately large weight in the analysis. In this study, there are many
observations to choose from that are very close neighbors even if not the closest
neighbor. Rather than limit the matches to the absolutely closest match, then, the following
method was used. All counties were sorted according to their propensity score. If two casino
counties shared the same control county as their nearest neighbor, the one with the closest
unused casino county was matched to the unused county, provided that the unused casino county
was closer than any other casino county. Otherwise, the closest county was simply used multiple
times. By using this method, 165 counties were chosen as comparisons for the 188 casino
counties, with one county used four times and 20 counties used twice as a control.
Once the comparison group was formed, mean differences in outcomes were computed
for the matched pairs. Of some concern in applying a matching estimator is the existence of
overlapping support. One paradoxical issue in applying matching estimators arises when noting
that a model which estimates treatment probabilities extremely well will sort the data into two
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distinct groups that have little overlap in propensity scores. This issue comes into play
somewhat here. About 87% of non-casino counties have a predicted probability under 10%,
while only about 31% of casino counties fall in this region. Fortunately, there are 2876 non-
casino counties in the dataset, but only 188 casino counties so there are generally plenty of
counties for the control group. The longest distance between a treatment county and its match is
a propensity score distance of 0.0386, and the average distance is just 0.000051.
Results are provided in the first column of Table 5. The outcome measures are the
percentage changes in median home prices (MEDIANVALUE), median income
(MEDIANINCOME), median rent (MEDIANRENT), county population (POPULATION),
county employment (EMPLOYMENT), county housing units (UNITS), and housing units in the
county constructed since 2000 (NEWUNITS). This specification indicates that casinos are
associated with about a 3% increase in population, employment, and new housing units, while
impacts on incomes, house prices, and rents are not statistically significant. An examination of
the signs shows that house prices in casino counties fell relative to their control group, and that
incomes rose, suggesting that casinos are associated with a reduction in quality of life, but the
large variances suggest that this result should be interpreted with caution.
The logit model was estimated and propensity scores were generated for three
subsamples, with results presented in Table 5, Columns 2-4. The first subsample excluded
counties with only a non-Native American casino. There was still generally strong overlapping
support, with the largest matched distance increasing only to 0.0529 and the average distance
between matches at just 0.0010. The second subsample excluded counties with only a Native
American casino, and overlapping support was still generally good. The third subsample
includes counties with less than 100,000 people, and support is generally good with the
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exception of Starr County, TX, mentioned above, whose nearest match is a probability distance
of 0.1262 away. Otherwise, the largest distance in propensity scores is 0.028. The results of
these three specifications generally find no statistically significant impact on the outcome
measures, except for a 5.7% increase in employment in non-Native counties.
Fixed bandwidth distance-weighted matching
One shortcoming of the one-to-one nearest neighbor matching method described above is
that it unnecessarily removes a great deal of information from the analysis by limiting the control
group to a small subset of observations. An alternative method is to choose a bandwidth for each
casino observation and use all control observations within that propensity score distance to form
the control group. A bandwidth of 0.05 was chosen, and for each observation in the control
group, a weight was placed on it so that observations closer to the casino county were given
heavier weight. A number of weighting methods have appeared in the literature (for example,
Heckman, Ichimura and Todd 1997, Todd 1999, McMillen 2004). This literature suggests that
weighting function should be chosen to ensure consistency in estimation and identifies a number
of appropriate weighting functions. The estimator chosen here is the biweight kernel. Weights
are given to each observation by the following kernel formula:
K=15/16(1 – (di/b)2)2 (7)
where di is the distance from the control observation to the treatment observation, and b is the
bandwidth. The weights are then normalized to sum to one for each observation. The
normalized weights are used to create a comparison observation for each treatment observation,
and estimation proceeds as above. In the dataset analyzed here, using this method assigns
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positive weight to each non-casino county.5 At least two observations were used to create each
comparison observation, and in some cases, over 2000 observations fell within the bandwidth.
The results from this method are presented in Table 6. The mean differences in outcomes
are presented for the full sample, non-Native casino counties, and Native casino counties. In the
full sample, casinos significantly increase population, employment, and new construction, but it
is apparent from inspecting the last two columns of Table 6 that these increases are driven almost
entirely by the Native casino counties. The estimated impact of Native American casinos on
population, employment, housing units, and new housing units is positive and on the order of
magnitude of approximately 3-5%, while the impact of non-Native counties is negatively signed
and statistically insignificant. Non-Native counties see a statistically significant fall in house
prices on the order of about 8% and an insignificant, negative effect on wages. This is
inconsistent with an improvement in the quality of life.
Nearest neighbor distance-weighted matching
An alternative to a fixed bandwidth is to choose a fixed number of nearest neighbors and
allow the bandwidth to vary. Either a simple average or weighting method can be used to create
the comparison observations. In this case, the five nearest neighbors were used and a biweight
kernel placed heavier weight on the nearest observations. The largest bandwidth needed to find
five nearest neighbors was 0.21, and five counties required a bandwidth greater than 0.10.
Nearly all casino counties had a bandwidth of less than 0.01. Results from this approach are
presented in Table 7. This specification yields very similar results to the fixed bandwidth
approach. Population, employment, housing units, and new housing units all grow by a
5 This is not generally true, but is for this sample.
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statistically significant amount of 3-5% in areas with Native American casinos, and house prices
fall in areas with non-Native casinos.
Split-kernel distance weighted matching
The assumption implicit in this approach so far is that errors are not correlated across
observations. A byproduct of this assumption is that comparison counties are sometimes not
intuitively appealing. For instance, in the one nearest neighbor matching method, the
comparison county for Orleans Parish, LA (New Orleans, population 484,000) is Apache
County, AZ, a geographically large, rural county with about 63,000 residents. If there are
differences in the impact of casinos on outcomes that are correlated across different groups of
counties, then placing additional restrictions on the matches can improve the estimator. Two
such groupings are examined here, region and county population. If there are regional
characteristics influencing outcomes that are not captured by the propensity score, forcing the
matches to come from the same region will eliminate the bias in the error term caused by
unobservables which are correlated with region. Additionally, if the size of the county
influences the outcome variables in some unobservable way, constraining the matches to come
from similarly sized counties will reduce the unobserved variables bias to the extent that the
unobservables are correlated with county size. The split kernel approach applied here loosely
follows McMillen (2004) and constrains the mean outcome to be constant across regions and
county sizes. This differs from the locally weighted regression model in McMillen (2004),
which allows effects to vary across different values of the explanatory variables and the locally
weighted regression model in Todd (1999), which allows the treatment effect to vary across
different values of the propensity score. The assumption here is that errors are correlated across
20
regions and county sizes, but the effect of casinos on outcomes does not vary across regions or
county sizes. An alternative weighting function is considered here.
The matching estimator works by calculating the mean impact of treatment on the treated,
where the observed treatment effect in each county is given by the following equation:
∆i = Yi – Yj (8)
Yi is the observed outcome in casino county i, and Yj is the observed outcome in matched
county j. Note that Yj is an amalgamation of outcomes from each county matched with county i
by the propensity score matching process. Assume Yi and and Yj are given by the following
functions:
Yi = f(Xi) + g(Ci) + εi (9)
and
Yj = f(Xj) + εj (10)
where f(X) represents non-casino impacts on the outcome, g(C) represents the casino impacts on
the outcome, and ε is an assumed independent random error. By using propensity score
matching, as shown by Rosenbaum and Rubin (1983), E[f(Xi) – f(Xj)] = 0, and g(Cj) = 0, since
the treatment counties do not have casinos. Then ∆i reduces down to the casino impact plus a
random error term.
Suppose however that the errors are not random, but systematic. In particular, suppose
that the errors are correlated by the geographic regions of the country. Then (9) and (10) become
Yi = f(Xi) + g(Ci) + µi + εi (9)’
and
Yj = f(Xj) + g(Cj) + µj + εj (10)’
where the µ’s are region-specific error terms. Then the estimated effect becomes
21
∆i = g(Ci) + (µi - µj) + (εi - εj). (11)
The term (µi - µj) represents bias that occurs from ignoring this correlation between outcomes
and regions.
One solution to this problem is to constrain the matched control counties to come from
the same region. Then µi = µj, and this bias is eliminated. To do that, the weighting function
needs to be modified to give zero weight to matched counties from other regions. This is fairly
straightforward. Define a function M(i,j) where M=1 if i and j are in the same region, and M=0
otherwise. Combining this with the biweight kernel function to place higher weights on
observations that are closer in propensity score yields the following weighting function.
W(i,j) = [15/16(1 – (dj/b)2)2] M(i,j). (12)
These weights are then normalized to sum to one for each match. This weighting function will
eliminate the bias present in equation (14). Any other correlations in the error term can be
corrected in identical fashion. In this case, define a function N(i,j) where N=1 if i and j are of
similar size, and N=0 otherwise. Then
W(i,j) = [15/16(1 – (dj/b)2)2] M(i,j) N(i,j) (13)
constrains matched counties to be of similar size and from the same region.
The cost of improving the estimator in this fashion is that the more constraints placed on
the matched counties, the more difficult it becomes to find regions of overlapping support.
In the first split-kernel specification, a bandwidth of 0.10 was used, with observations
weighted by a biweight kernel if they fell within the same region and given zero weight if they
did not. There were four counties which had no counties suitable for a match, so they were
dropped from the analysis. Each of the eliminated counties had a predicted probability of
between 67% and 90% of having a casino, which made the data for predicted probabilities above
22
67% somewhat sparse, but there were still 13 counties with casinos in this range. The results are
presented in Table 8. Again, Native American casinos generate economic activity in the form of
employment growth, population growth, and new housing units in their counties. In this
specification, housing prices fall across the board, but the impact on rents in non-Native casino
counties is positive, significant, and rather large at 5.6%.
An additional restriction was added to the model to force comparisons to come from
counties of similar size. This is particularly important because of the heterogeneity of casino
impacts in areas of different population density identified in Wenz (2006). Note that non-Native
casinos choose counties with much larger populations than the average non-casino county.
Constraining the matches to come from similarly sized counties ensures that the measured effects
are not a product of the differences in effects due to city size. Comparisons were restricted to
counties within 50% to 150% of the casino county population. Results are presented in Table 9.
In this specification, as in the others, the Native casinos have statistically significant and positive
impacts on employment, population, housing units and new housing units on the order of
magnitude of between 3% and 4%. Here, however, the impact on housing prices is insignificant
and positively signed. Non-Native casino counties tended to be much larger on average than
non-casino counties, so the comparisons tended to come from smaller counties. If smaller
counties saw house prices rise at a different rate than large counties, independent of the casino
location decision, then the fall in relative house prices would be a function of county size rather
than the casino. By constraining the matches to come from similarly sized counties, this
correlation between unmeasured characteristics and city size is removed. Additionally, and more
importantly, the negative relationship between non-Native casinos and house prices disappears in
this specification.
23
Conclusions and implications
Assessing the impact of casino gambling on economic outcomes requires some
understanding of what outcomes might have occurred had the casino not been present. The
method applied here to construct a counterfactual is that of propensity score matching.
Based on the probability of each county opening a casino, treatment (casino) counties were
paired with control group counties. The propensity scores play an important role in weighting
the control group in a way that makes it as if the treatment and control observations came from
the same underlying density function.
Propensity score matching can be implemented in a number of different ways, and it is
helpful to investigate whether the results are sensitive to the exact implementation method.
Here, the results are very consistent across the nearest neighbor method, the fixed bandwidth
method, and a split-kernel method developed in this paper that places additional restrictions on
the match. Native American casinos are positively and statistically significantly associated with
an increase in population, employment, and housing units in their counties. These measures
grow 3%-5% faster in non-Native counties than in native counties. In some specifications, non-
Native casinos were associated with falling housing prices, but when restricting the match group
to counties with similar population sizes, this effect disappeared. This restriction is important
and appropriate due to the heterogeneity of casino impacts by population.
Casinos do not have a discernable impact on quality of life. In the final model
specification, they do not significantly impact house prices, wages, or rents, though Native
American casinos do generate some additional economic activity.
24
References American Gaming Association. State of the States: The AGA Survey of Casino
Entertainment. Washington, D.C., 2006. Blomquist, G. C., Berger, M. C., and Hoehn, J. P.: New estimates of quality of life in
urban areas. American Economic Review. 78(1): 89-107, 1988. Eadington, W. R.: The economics of casino gambling. Journal of Economic
Perspectives. 13(3): 173-192, 1999. Evans, W. N. and Topoleski, J. H.: The social and economic impact of Native American
casinos. NBER Working Paper No. 9198, 2002. Grinols, E. L. and Mustard, D. B.: Casinos, Crime, and Community Costs. Review of
Economics and Statistics, 88(1): 28-45, 2006.
Grinols, E. L. and Mustard, D. B.: Business profitability versus social profitability: Evaluating industries with externalities, the case of casinos. Managerial and Decision Economics, 22: 143-162, 2001.
Gyuorko, J. and Tracy, J.: The structure of local public finance and the quality of life.
Journal of Political Economy 99(4): 774-806, 1991. Heckman, J.J., Ichimura, H. and Todd, P.: Matching as an econometric evaluation
estimator. Review of Economic Studies. 65(2): 261-294, 1998. McMillen, D.P.: Locally weighted regression and time-varying distance gradients. In:
Spatial Econometrics and Spatial Statistics. Getis, A., Mur, J., and Zoller, H. (eds.), pp. 232-249, New York, Palgrave Macmillan, 2004.
Roback, J.: Wages, rents, and the quality of life. Journal of Political Economy, vol.
90(6): 1257-1278, 1982. Rosen, S.: Hedonic prices and implicit markets: Product differentiation in pure competition. Journal of Political Economy. 82(1): 34-55, 1974. Rosenbaum, P.R. and Rubin, D.B.: The central role of the propensity score in
observational studies for causal effects. Biometrika. 70(1): 41-55, 1983. Todd, Petra. A Practical Guide to Implementing Matching Estimators. Unpublilshed
Manuscript, 1999. Walker, D. M.: Methodological issues in the social cost of gambling. Journal of
Gambling Studies. 19(2): 149-183, 2003.
25
Walker, D. M. and Barnett, A. H.: The social costs of gambling: An economic perspective.” Journal of Gambling Studies, 15(3):181-212, 1999.
Wenz, M. Casino Gambling and Economic Development. Ph.D. Dissertation, University of
Illinois at Chicago. 2006.
26
Figure 1. Map of casino locations in the United States as of the year 2000.
27
Table 1. Binomial logit coefficient estimates—full model
Parameter
(Std. Error) Marginal
Effect Dependent Variable: Any Casino
Intercept
-11.0957 (2.165)
***
MANUF
-0.0109 (0.015)
-0.0005
UNEMP
6.5704 (3.092)
**
0.2828
VACANCY
0.0276 (0.009)
***
0.0012
lnPOP
0.7496 (0.147)
***
0.0323
lnLANDAREA
0.2097 (0.156)
0.0090
URBANPCT
0.0025 (0.006)
0.0001
lnPOP50IN
-0.3880 (0.121)
***
-0.0167
lnPOP50OUT
0.0130 (0.019)
0.0006
NEARESTOUT
-0.0051 (0.002)
**
-0.0002
FISCAL
0.0022 (0.008)
0.0001
FISCALCHG
0.0014 (0.003)
0.0001
VOTEDEM
0.0259 (0.014)
*
0.0011
VOTEPEROT
0.0326 (0.026)
0.0014
CATHRELIG
0.0055 (0.007)
0.0002
FUNDRELIG
-0.0362 (0.011)
***
-0.0016
NATIVEPOP
0.0469 (0.009)
***
0.0020
COASTAL
1.0417 (0.257)
***
0.0448
28
Parameter
(Std. Error)
Marginal
Effect
RIVER
1.5386 (0.319)
***
0.0662
REASTNORTHCENTRAL
1.9018 (0.548)
***
0.0818
RWESTNORTHCENTRAL
2.3837 (0.575)
***
0.1026
RSOUTHATLANTIC
0.0591 (0.803)
0.0025
REASTSOUTHCENTRAL
2.3931 (0.752)
***
0.1030
RWESTSOUTHCENTRAL
1.3990 (0.669)
**
0.0602
RMOUNTAIN
2.1895 (0.636)
***
0.0942
RPACIFIC
3.4726 (0.590)
***
0.1494
Likelihood Ratio (R) 462.08
Upper Bound of R (U) 1413.5
McFadden's LRI 0.3269
*significant at the 90% confidence level; **significant at the 95% confidence level; ***significant at the 99% confidence level.
Source: Wenz, M. Casino Gambling and Economic Development. Ph.D. Dissertation, University of Illinois at Chicago, 2006.
29
Table 2. Data sources for casino location model. Variable Description Source CASINO Dummy variable
identifying whether there are any casinos in the county.
www.gamblinganswers.com, accessed October 2003.
UNEMP County Unemployment Rate 1990
U.S. Census of Population and Housing, 1990, Summary Tape File 3
MANUF % Employees in county employed in manufacturing industry, 1990
U.S. Census of Population and Housing, 1990, Summary Tape File 3
VACANCY % Vacant Housing Units, 1990
U.S. Census of Population and Housing, 1990, Summary Tape File 3
DENSITY Population per square mile, 1990
U.S. Census of Population and Housing, 1990, Summary Tape File 3
POP50IN Population for census block groups within 50 miles of the county, inside the same state, 1990.
U.S. Census of Population and Housing, 1990, Summary Tape File 1 and Summary Tape File 3
POP50IN Population for census block groups within 50 miles of the county, outside the same state, 1990.
U.S. Census of Population and Housing, 1990, Summary Tape File 1 and Summary Tape File 3
NEARESTIN Distance from county centroid to nearest casino outside the county and in the same state.
Casino locations from www.gamblinganswers.com; County Centroids computed using Maptitude computer software and TIGER/Line files from the U.S. Census.
NEARESTOUT Distance from county centroid to nearest casino outside the county and outside the same state.
Casino locations from www.gamblinganswers.com; County Centroids computed using Maptitude computer software and TIGER/Line files from the U.S. Census.
FISCAL Ratio of county government revenues-expenses/expenses
County and City Data Books. Retrieved February 2006 from the University of Virginia, Geospatial and Statistical Data Center: http://fisher.lib.virginia.edu/collections/stats/ccdb/.
Variable Description Source
30
FISCALCHG Percentage change in county expenditures, 1982-1987
County and City Data Books. Retrieved February 2006 from the University of Virginia, Geospatial and Statistical Data Center: http://fisher.lib.virginia.edu/collections/stats/ccdb/.
VOTEPEROT Percentage of Ross Perot votes for President, 1992
County and City Data Books. Retrieved February 2006 from the University of Virginia, Geospatial and Statistical Data Center: http://fisher.lib.virginia.edu/collections/stats/ccdb/.
VOTEDEM Percentage of Democratic votes for President, 1992
County and City Data Books. Retrieved February 2006 from the University of Virginia, Geospatial and Statistical Data Center: http://fisher.lib.virginia.edu/collections/stats/ccdb/.
RELIG Percentage of county residents adhering to fundamentalist religions, 1990
Bradley, et.al. (1992). Churches and Church Membership in the United States, 1990. Accessed at the Association of Religious Data Archives, www.ARDA.com, accessed February 2006.
NATIVEAMER Percentage of county residents of American Indian/Alaska Native Race
U.S. Census of Population and Housing, 1990, Summary Tape File 3
Source: Wenz, M. Casino Gambling and Economic Development. Ph.D. Dissertation, University of Illinois at Chicago, 2006.
31
Table 3. Most and least likely counties to have casinos 10 Most Likely Counties Without A Casino Predicted Probability Imperial County, California 86.4%Cook County, Illinois 85.4%Lane County, Oregon 74.1%Starr County, Texas 69.3%Apache County, Arizona 68.6%Spokane County, Washington 66.6%Monterey County, California 63.5%Sonoma County, California 61.9%Rio Arriba County, New Mexico 61.6%Multnomah County, Oregon 56.1% 10 Most Likely Counties With A Casino Predicted Probability Los Angeles County, California 89.6%St. Louis County, Minnesota 89.3%King County, Washington 84.0%San Diego County, California 82.5%Humboldt County, California 81.5%St. Louis County, Missouri 73.0%San Bernardino County, California 69.9%Orleans Parish, Louisiana 67.8%Yuma County, Arizona 67.5%Riverside County, California 67.4% 10 Least Likely Counties With A Casino Predicted Probability Swain County, North Carolina 0.4%Ohio County, Indiana 0.4%Neshoba County, Mississippi 0.4%Massac County, Illinois 0.7%Gilpin County, Colorado 1.0%Allen Parish, Louisiana 1.1%Bossier Parish, Louisiana 1.3%Doniphan County, Kansas 1.9%Clarke County, Iowa 2.0%Oneida County, New York 2.1%
32
Table 4. Distribution of predicted probabilities in casino/non-casino counties.
Predicted Probability of Opening a Casino
Number of Counties With Casino
Number of Counties Without a Casino
<1% 5 1205 1-5% 18 974
5-10% 36 319 10-20% 32 212 20-40% 42 123 40-60% 35 34 60-70% 14 6 70-80% 1 1 80-90% 5 2
90-100% 0 0
33
Table 5. One nearest neighbor match
All Casino Counties
Native Casino Counties
Non-Native Casino
Counties
Small (<100,000)
Casino Counties
Mean Effect (t-statistic)
Mean Effect (t-statistic)
Mean Effect (t-statistic)
Mean Effect (t-statistic)
mdiffMEDIANVALUEpct -2.76% (-0.88)
-3.52% (-0.87)
1.07% (0.20)
0.09% (0.03)
mdiffMEDIANINCOMEpct 1.14% (0.86)
-0.12% (-0.07)
2.79% (1.08)
2.51% (1.40)
mdiffMEDIANRENTpct 1.25% (0.85)
0.08% (0.03)
0.14% (0.05)
0.43% (0.22)
mdiffPOPULATIONpct 3.23% (2.19)
* 1.97% (0.98)
2.22% (0.92)
1.50% (0.73)
mdiffEMPLOYMENTpct 3.14% (1.90)
* 1.48% (0.70)
5.74% (2.02)
* 2.38% (1.02)
mdiffUNITSpct 1.95% (1.44)
1.92% (1.07)
1.66% (0.87)
0.60% (0.34)
mdiffNEWUNITSpct 2.59% (2.08)
* 2.05% (1.25)
2.58% (1.33)
0.95% (0.57)
*Statistically significant at a 90% confidence level.
34
Table 6. Match with bandwidth=0.05, distance-weighted
All Casino Counties
Non-Native Casino Counties
Native Casino Counties
Mean Effect (t-statistic)
Mean Effect (t-statistic)
Mean Effect (t-statistic)
mdiffMEDIANVALUEpct -1.52% (-0.64)
-8.02% (-1.98)
* 1.23% (0.43)
mdiffMEDIANINCOMEpct 0.89% (0.78)
-1.22% (-0.70)
1.79% (1.24)
mdiffMEDIANRENTpct 0.79% (0.68)
2.69% (1.17)
-0.02% (-0.02)
mdiffPOPULATIONpct 2.64% (2.30)
* -1.29% (-0.59)
4.30% (3.25)
*
mdiffEMPLOYMENTpct 3.27% (2.61)
* -0.79% (-0.29)
4.99% (3.68)
*
mdiffUNITSpct 1.46% (1.45)
-1.80% (-1.06)
2.85% (2.31)
*
mdiffNEWUNITSpct 1.94% (2.08)
* -1.20% (-0.70)
3.27% (3.00)
*
*Statistically significant at a 90% confidence level.
35
Table 7. Match with 5 nearest neighbors, distance-weighted
All Casino Counties
Non-Native Casino Counties
Native Casino Counties
Mean Effect (t-statistic)
Mean Effect (t-statistic)
Mean Effect (t-statistic)
mdiffMEDIANVALUEpct
-1.51% (-0.59)
-7.50% (-1.73)
*
1.03 (0.33)
mdiffMEDIANINCOMEpct
0.99% (0.83)
-1.39% (-0.79)
2.01 (1.32)
mdiffMEDIANRENTpct
1.30% (1.05)
3.78% (1.59)
0.25 (0.17)
mdiffPOPULATIONpct
3.24% (2.65)
*
-0.11% (-0.05)
4.66 (3.32)
*
mdiffEMPLOYMENTpct
3.71% (2.76)
*
0.05% (0.02)
5.27 (3.58)
*
mdiffUNITSpct
1.95% (1.79)
*
-0.75% (-0.39)
3.09 (2.37)
*
mdiffNEWUNITSpct
2.42% (2.43)
*
-0.10% (-0.05
3.49 (3.03)
*
*statistically significant at a 90% confidence level.
36
Table 8. Match with bandwidth=0.10, distance-weighted, constrained by region
All Casino Counties
Non-Native Casino Counties
Native Casino Counties
Mean Effect (t-statistic)
Mean Effect (t-statistic)
Mean Effect (t-statistic)
mdiffMEDIANVALUEpct -5.08% (-2.37)
* -5.18% (-1.68)
* -5.04% (-1.82)
*
mdiffMEDIANINCOMEpct -0.09% (-0.08)
-2.70% (-1.42)
0.99% (0.69)
mdiffMEDIANRENTpct 0.62% (0.54)
5.58% (2.80)
* -1.43% (-1.05)
mdiffPOPULATIONpct 2.47% (2.37)
* -0.07% (-0.04)
3.52% (2.93)
*
mdiffEMPLOYMENTpct 2.37% (2.10)
* -0.09% (-0.04)
3.39% (2.68)
*
mdiffUNITSpct 1.48% (1.54)
-1.23% (-0.66)
2.61% (2.35)
*
mdiffNEWUNITSpct 2.11% (2.34)
* -0.88% (-0.47)
3.35% (3.33)
*
*Statistically significant at a 90% confidence level.
37
Table 9. Match with bandwidth=0.10, distance-weighted, constrained by region and population.
All Casino Counties
Non-Native Casino
Counties
Native Casino
Counties
Mean Effect (t-statistic)
Mean Effect (t-statistic)
Mean Effect (t-statistic)
mdiffMEDIANVALUEpct -1.94% (-0.89)
0.77% (0.30)
-3.05% (-1.05)
mdiffMEDIANINCOMEpct 0.70% (0.65)
1.24% (0.70)
0.48% (0.36)
mdiffMEDIANRENTpct 0.79% (0.65)
3.28% (1.38)
-0.23% 0.17)
mdiffPOPULATIONpct 2.48% (2.16)
* -0.57% (-0.25)
3.73% (2.84)
*
mdiffEMPLOYMENTpct 2.79% (2.27)
* 0.68% (0.26)
3.65% (2.66)
*
mdiffUNITSpct 1.98% (1.97)
* -1.72% (-0.86)
3.49% (3.09)
*
mdiffNEWUNITSpct 2.35% (2.51)
* -0.74% (-0.38)
3.62% (3.51)
*
*Statistically significant at a 90% confidence level.