Social preferences are stable over long periods of time

We measure people’s prosocial behavior, in terms of voluntary money and labor time contributions to an archetypical public good, a bridge, and in terms of voluntary money contributions in a public good game, using the same non-student sample in rural Vietnam at four different points in time from 2005 to 2011. Two of the experiments are natural experiment, one is a field experiment and one is a public good experiment. Since the experiments were conducted far apart in time, the potentially confounding effects of moral licensing and moral cleansing are presumably small, if existing at all. Despite large contextual variations, we find a strong positive and statistically significant correlation between voluntary contributions in these experiments, whether correcting for other covariates or not. This suggests that pro-social preferences are fairly stable over long periods of time and contexts.