Experiments from last week - University of...

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Experiments from last week. Profit for seller: Price minus cost. Profit for buyer: Value minus price Line up sellers from lowest to highest and plot costs. Get_____ Line up buyers from highest to plot values. Get.______ equilibrium is price = _____ and Q = ____

Transcript of Experiments from last week - University of...

Page 1: Experiments from last week - University of Minnesotausers.econ.umn.edu/.../instructor_ta/experiment_results.docx · Web viewExperiments from last week. Profit for seller: Price minus

Experiments from last week.Profit for seller: Price minus cost.Profit for buyer: Value minus price

Line up sellers from lowest to highest and plot costs. Get_____

Line up buyers from highest to plot values. Get.______

equilibrium is price = _____ and Q = ____

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Supply and Demand for Section 001AL

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Highest value buyer: value of 60. At competitive price has profit of:______

Lowest cost seller: cost of 10. At competitive price has a profit of: _______

Average between them is 25 in profit.

Some buyers have a value of 40 and at competitive price have profit of ______

At the perfectly competitive price, on average profit per student (per round) is $12.00

Let’s look what happened for 001AL:

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In the figure, blue squares represent transactions in the first round. There is an

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interesting pattern in the auctions. In the first round of each auction, transaction prices are all over the place, one at $10, a six at around $50, and so on. But most the trades taking place away from the $40 benchmark are low price trades, e.g. $10, $13. So even though there is symmetry in that the buyers are mirror images of the seller. Students are more willing to sell at a low price than buy at a high price. Later in the auction, most trades take place near price equal to $40.

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Average Realized Profit By Round (Equals 12.00 with perfect competition)

Round

Across All 12

Experiments

Large Lectures9:05A-L

9:30M-Z

10:10A-L

10:35M-Z

1 10.32 10.14 9.55 10.38 11.102 10.98 11.25 10.25 10.79 11.463 11.39 11.50 10.91 11.94 11.304 11.38 11.26 11.82 11.73 11.755 11.17 10.96 11.53 11.39 11.73

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The previous table shows the results across different lectures. Recall that the average profit is $12 at the perfectly competitive outcome in this market. We can see the learning, by looking at what is happening to the average profit in the later rounds. Profit starts low and rises in the later rounds.

Next, let's look at the highest scoring trades. To determine who played the best, we have to adjust scores to take into account that some sellers draw low costs and some buyers draw high values.(Note: everyone who participated in auction gets 1 bonus point added to HW2 If your adjusted profit is in top half, your get an extra bonus point.)

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How buyer score is calculated: 1. Calculate buyer’s profit when purchase a book at $40 (the competitive price). 2. Adjustment (per round) is difference between that and $12 (average profit at competitive price).

Example 1: Buyer has value of $45.1. Profit at $40 purchase price = $5 (= $45-$40).2. Adjustment (per round) = +$7 (to get to $12 per round)

Example 2: Buyer has value of $60.1. Profit at $40 purchase price = $20 (= $60-$40).2. Adjustment (per round) = −$8 (to get to $12 per round)

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Bottom line: If a buyer, we start you at 12 and give you one point for

every dollar below $40 in the price of a book you buy. If a seller, start you at 12 and give you one point for every

dollar above $40 in the price of a book you sell.

Who are the superstar traders? (The highest point getters in each auction?)

They all did it the same way . All buyers (not sellers) Snapped up a great deal at least once and did OK the

other times.

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Superstar for 001AL. Buyer value 51 predicted profit = 51-40 = 11 (adjustment is +$1)

Round Price paid

Actual Profit

Adjusted Score

1 20 31 322 25 26 273 37.80 13.2 14.24 40 11 125 40 11 12

(total Adjusted Score =97.20)Superstar for 001MZ. Buyer value 39

predicted profit = −$1 (adjustment +13 if sale)Round Price

paidActual Profit

Adjusted Score

1 15 24 372 30 9 223 35 4 174 23 16 295 39 0 13

(total Adjusted Score =118)

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Superstar for 017AL. Buyer value 49 predicted profit = 49-40 = 9 (adjustment is +3)

Round Price paid

Actual Profit

Adjusted Score

1 12 37 402 36 13 163 38 11 144 40 9 125 39.31 9.69 12.69

(total Adjusted Score =94.69)Superstar for 017MZ. Buyer value $45

predicted profit = 45-40 = 5 (adjustment is +7)

Round Price paid

Actual Profit

Adjusted Score

1 13.99 31.01 38.012 34.99 10.01 17.013 40 5 124 41 4 115 41 4 11

(total Adjusted Score =89.02)

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And the superstars are....

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While most research in economics is based on data from actual markets, analysis of data from experimental markets plays some role in the field.

Can see how we can use this data to study speed of learning

Can also potentially use this to study characteristics of success. o Links to course grades?o Do students with an interest in business (e.g. in

Carlson) tend to do better?

Let’s take an exploratory look with data from earlier years.

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Relationship between Econ 1101 Class Performance (Quartile) Adjusted Profit on Experiment

Course

Performanc

e(Quart

ile)

Adjusted ProfitAverage

Years

2009-

2011

2009

2010

2011

155.43

55.68

55.09

55.45

2 54. 55. 54. 53.

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58 09 87 88

353.66

55.12

54.29

51.78

450.25

51.30

49.02

50.29

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Relationship between Econ 1101 Class Performance (Quartile) Being late for experiment

(robot plays first round, student plays later rounds)

Course

Performanc

e(Quart

ile)

Percent of Students Late

Average

Years

2009-

2011

2009

2010

2011

1 2.2 1.7 2.6 2.4

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2 2.3 1.7 3.5 2.03 2.3 1.7 2.9 2.44 5.9 6.9 5.7 5.2

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Year after year, the students who tend to do poorly in this class are the same ones who tend to show up late for the auction.

More generally students who do poorly in grades tend to

earn less later in life than their peers who do well in grades. o There are many factors at work here.o One potential factor: being late for things (sending

resumes out late, etc.)o Certainly true in experiment. If robot plays for you,

you get zero!