We conducted large-scale lost letter experiments in Beijing, a megacity with more than 21 million residents, to test if the observed altruistic attribute of the letter recipient would induce more passersby to return the lost letters. The treatment letters were addressed to a nationally renowned...

A substantial and rapidly growing literature has developed around estimating earnings gains from two-year college degrees using administrative data. These papers almost universally employ a person-level fixed effects strategy to estimate earnings premia net of fixed attributes. We note that the...

Prior research suggests that gender differences in hours worked play an important role in the gender pay gap. Yet common estimates of the wage returns to hours worked are close to zero, implying that hours differences cannot account much for the gender wage gap, even though men work more hours...