We exploit variation in National Insurance contributions (NICs) - the UK's system of social security contributions - and a large panel dataset to examine the effects of 35 years of employee and employer NICs reforms on labour cost (gross earnings plus employer NICs), hours of work and labour...

We analyze how separations responded to arbitrary differences in own and peer wages at a large U.S. retailer. Regression-discontinuity estimates imply large causal effects of own wages on separations, and on quits in particular. However, this own-wage response could reflect comparisons either to...

Large and persistent differences across industries in wages paid for given occupations have commonly been observed. Recently, the efficiency wage model (EWM) has been advanced as an explanation for these wage differentials. The shirking version of the EWM assumes a trade-off between...