A Distributional Analysis of Changes in Earnings Inequality among Unionized and Nonunionized Male Workers in the United States: 1982-1990

Abstract

The major explanations for the dramatic changes in earnings inequality in the United States through the 1970s and 1980s have concentrated on a combination of supply-side, demand-side, and institutional factors (Levy and Murnane 1992). The decline in union density has been offered as one institutional factor that has contributed to increased earnings inequality, in part because the less well-educated tend to be more highly organized (Lemieux 1993; Card 1992; Freeman 1991; Blackburn, Bloom, and Freeman 1990). In view of the coincident dramatic decline of unionism in the United States during the late 1970s and 1980s, one issue concerns whether changes in earnings inequality have differed systematically among unionized and nonunionized workers. Little systematic distributional analysis of changes in earnings by union status has developed, yet Freeman (1991) found that dispersion grew among both union and nonunion groups. This paper addresses this issue by empirically examining changes in the structure of the earnings distribution among unionized and nonunionized male workers, respectively, in the United States, over the 1982 to 1990 period. This analysis employs standard distributional measures but extends previous studies by applying recently developed techniques of statistical inference to test for change.