Discussion Papers 745
6 Regression analysis
situation never occurred. We conclude that the choice of private remuneration after team
remuneration tends (just failing statistical significance) to be due to the fact that the partici-
pant had contributed a higher effort than the other player.
Conclusion 5: In both SYM treatments, we observe reciprocity in the effort choice. In the
VOLUNTARY ASYM treatment, only the low-cost player observes the recipro-
city rule. The choice of private remuneration can be interpreted as a signal of
disapproval of the low effort of the other player in the previous team remune-
ration mode.
6 Regression analysis
In this section we complement the non-parametric data analysis presented above by a regres-
sion analysis. In Section 5.1, we examine the choice of remuneration for the VOLUNTARY
SYM and VOLUNTARY ASYM treatments. In Section 5.2, we examine the effort choice for all
treatments. We shall see that the parametric regression results are quantitatively and qualitati-
vely consistent with our non-parametric observations.
6.1 Remuneration mode
We examine the participants’ choice of the remuneration mode in a parsimonious random
effect probit model on the decision to choose team remuneration. The decision variable “vo-
luntary teaming” is equal to “1” if the participant chooses team remuneration and “0” other-
wise. Explanatory variables are “1st period”, which is equal to “1” for the first period and “0”
otherwise, and “last 5 periods”, which is equal to “1” for the last five periods and “0” other-
wise. These two dummy variables account for first-period and end-game effects.
We also construct the explanatory variables “partner’s effort below a strategic level” and
“partner’s effort above a strategic level” based on the following hypothesis. A participant
chooses team remuneration if he expects to earn a higher payoff than under private remunera-
tion. Assume that he chooses his dominant strategy in team remuneration and, thus, to achieve
a higher or equal payoff than in private remuneration, he needs a minimum effort from his
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