This article analyzes the effect of labor unions on overtime compensat
ion and overtime hours. Estimates from May 1985 Current Population Sur
vey data indicate that unionization increases the prevalence of premiu
m pay for overtime and reduces the incidence and extent of overtime ho
urs. Along with the finding of previous research that unionized worker
s are more susceptible to temporary layoffs, these results are consist
ent with a model in which unions use overtime pay to stabilize working
hours and expand membership.