Table 6.

Cooperation dynamics

	Contribution to the public good
	Tobit estimation				Multilevel mixed effects estimation
	No punishment (left censored)		Punishment (right censored)		No punishment		Punishment
Period	−1.037***	−1.042***	0.682**	0.711**	−0.731***	−0.737***	0.091***	0.093***
	(0.160)	(0.159)	(0.282)	(0.281)	(0.043)	(0.044)	(0.024)	(0.025)
Final period	−2.512***	−2.611***	−5.795***	−5.864***	−1.277***	−1.315***	−1.119***	−1.082***
	(0.881)	(0.907)	(1.797)	(1.863)	(0.408)	(0.420)	(0.233)	(0.241)
MTurk	5.421***	5.390**	4.193	8.282	4.218***	5.084***	0.893	2.009
	(1.867)	(2.130)	(4.904)	(5.919)	(1.394)	(1.466)	(1.249)	(1.320)
Age		0.120**		−0.003		0.028		−0.029
		(0.058)		(0.144)		(0.029)		(0.025)
Female		2.370**		−4.072		0.927*		0.118
		(0.976)		(2.595)		(0.516)		(0.438)
Single child		0.730		−1.096		0.051		−0.245
		(1.262)		(4.071)		(0.715)		(0.607)
Foreign		−1.042		6.286		0.801		0.401
		(2.557)		(4.622)		(1.196)		(1.065)
Membership		1.242		5.536		1.764***		1.520***
		(1.452)		(4.661)		(0.651)		(0.556)
Constant	11.402***	6.544**	29.601***	26.270***	12.451***	10.043***	15.871***	15.368***
	(1.650)	(2.778)	(4.232)	(6.756)	(1.246)	(1.530)	(1.109)	(1.348)
N	3200	3050	3200	3050	3200	3050	3200	3050
Chi2/F	34.45	15.35	3.75	1.96	503.80	496.65	25.67	32.03

Tobit and Multilevel mixed effects estimation, which allows for individual and group differences, as well as for treatment-specific residuals. ‘Period’ is period number; ‘Final period’ is a dummy for last period; ‘MTurk’ is a dummy for the MTurk sample; ‘Age’ is the participant’s age; ‘Female’ is a dummy for female participants; ‘Foreign’ is a dummy for participants who grew up outside the US; ‘Membership’ is a dummy for participants who were members of a social club. Robust standard errors clustered on groups for the Tobit model

* p < 0.1; ** p < 0.05; *** p < 0.01