@techreport{Chao2007,
author = {Chao, L.-W. and Kohler, H.P.},
title= {The Behavioral Economics of Altruism, Reciprocity, and Transfers within Families and Rural Communities: Evidence from Sub-Saharan Africa},
year = {2007},
URL = {http://repository.upenn.edu/parc_working_papers/9/},
}