Figure 3: Empirical distribution of average cooperation by economy(*)
(**)
Table 4: Cooperation in the first period of an economy
|
Number of |
Private |
Anonymous |
Private monitoring |
Public monitoring |
|
Average cooperation | ||||
|
73.5% |
70.5% |
84.5% |
87.0% | |
|
Frequency of cooperation in an economy | ||||
|
4 |
36% |
26% |
50% |
54% |
|
3 |
30% |
42% |
38% |
40% |
|
2 |
28% |
22% |
12% |
6% |
|
1 |
4% |
8% |
0% |
0% |
|
0 |
2% |
2% |
0% |
0% |
|
Frequency of cooperation in a match | ||||
|
2 |
58% |
51% |
71% |
75% |
|
1 |
31% |
39% |
27% |
24% |
|
0 |
11% |
10% |
______2%______ |
_______1%______ |
(*) Kolmogorov-Smirnov two-tail two-sample test on distributions confirms results from the Mann-Whitney
tests on the differences between averages. On one hand private monitoring and anonymous public
monitoring are not statistically different (10% confidence level, n1=n2=50). Conversely, private monitoring
with punishment and non-anonymous public monitoring are not statistically different. Treatments from the
two groups are instead statistically different at least at a 5% level.
(**) In each treatment the number of observations is 50 for “average” and “frequency of cooperation in an
economy” and 100 for “frequency of cooperation in a match.”
19