Discussion Papers 745
5 Experimental results
le point was not chosen in the asymmetric cases. Note that when the Pareto optimum lies at
the border of the strategy space so that participants have no opportunity to go above, either
intentionally or erroneously, this might cause the observed cooperation level to lie much
further below the Pareto optimum than it would otherwise.
Figure 1
Density of team effort in the VOLUNTARY and ENFORCED SYM treatments
■ enforced ■ voluntary
The average profit under enforced teaming is 191.73 (standard deviation of 120.56). It is
significantly higher than the team equilibrium profit of 187.5 (Wilcoxon test, 5-percent signi-
ficance), but lower than the joint profit-maximizing profit of 250 (Wilcoxon test, 2-percent
significance). It is also lower than the average profit of 220.08 under voluntary teaming; but
this difference is statistically not significant (u-test). The standard deviations of effort and
profit, such as the absolute difference between the two players’ effort levels are not signifi-
cantly different between the two treatments.
Comparing average effort and profit levels in the ENFORCED ASYM treatment to those in the
VOLUNTARY ASYM treatment, we observe that the profit of 75.98 (standard deviation of
151.41) of the high-cost player in the ENFORCED ASYM treatment is significantly lower than
in the VOLUNTARY ASYM treatment (u-test, 2-percent significance). Also, the standard de-
viation of the high-cost players’ team effort is higher in the enforced treatment (21.67) than in
the voluntary treatment (u-test, 10-percent significance). All other variables in the EN-
FORCED ASYM treatment, the low-cost players’ effort (31.14) and its standard deviation
17