We analyze how separations responded to arbitrary differences in own and peer wages at a large US 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 market wages or to peer wages. Estimates using peer-wage discontinuities show large peer-wage effects and imply the own-wage separation response mostly reflects peer comparisons. The peer effect is driven by comparisons with higher-paid peers—suggesting concerns about fairness. Separations appear fairly insensitive when raises are similar across peers—suggesting search frictions and monopsony are relevant in this low-wage sector.

We evaluate a tracking program in a large urban district where schools with at least one gifted fourth grader create a separate “gifted/high achiever” classroom. Most seats are filled by non-gifted high achievers, ranked by previous-year test scores. We study the program's effects on the high achievers using (i) a rank-based regres sion discontinuity design, and (ii) a between-school/cohort analysis. We find significant effects that are concentrated among black and Hispanic participants. Minorities gain 0.5 standard deviation units in fourth-grade reading and math scores, with persistent gains through sixth grade. We find no evidence of negative or positive spillovers on nonparticipants.