Previous research has found that union standard rate policies lower the dispersion of union wages and that unions indirectly raise nonunion wage levels, as firms weigh the probability of unionizing and wage costs. These two findings imply that unions lower the dispersion of nonunion wages since, for a given payroll, a nonunion firm can achieve the greatest reduction in the probability of unionism by giving raises to those who would benefit most from a union. This hypothesis is confirmed on Current Population Survey data: taking into account the endogeneity of unionism, ceteris paribus, nonunion wage dispersion is lower in more highly unionized industries.