This paper introduces new experimental designs to examine how conditional cooperation and punishment behaviours respond to the full range of variation in the contributions of others. It is shown that contributions become significantly more selfish-biased as others contribute more unequally,...

Many households have insufficient savings to handle moderate and routine consumption shocks. Many of these financially fragile households also have the highest lottery expenditures as a proportion of income. This combination suggests that prize-linked savings (PLS) accounts, combining security...