Five decades of CPS wages, methods, and union‐nonunion wage gaps at Unionstats.com

• Published date: 01 October 2023
• Author: David A. Macpherson,Barry T. Hirsch
• Date: 01 October 2023
• DOI: http://doi.org/10.1111/irel.12330

Industrial Relations. 2023;62:439–452. wileyonlinelibrary.com/journal/irel 439

1Department of Economics, Trinity University,

San Antonio, Texas, USA

2IZA-Bonn, Bonn, Germany

3Department of Economics, Andrew Young

School of Policy Studies, Georgia State

University, Atlanta, Georgia, USA

Correspondence

David A. Macpherson, Department of

Economics, Trinity University, One Trinity

Place, San Antonio, TX 78212-7200, USA.

Email: david.macpherson@trinity.edu and

dmacpher@trinity.edu

Abstract

Unionstats.com provides annual measures of union, nonun-

ion, and overall wages, beginning in 1973, compiled from

the U.S. Current Population Surveys. Regression-based

union wage gap estimates are presented economy-wide, for

demographic groups, and sectors (private/public, indus-

tries). Union wage gaps are higher in the private than in the

public sector, higher for men than women, roughly similar

for black and white men, and much higher for Hispanic

men than for Hispanic women. The database is updated

annually.

JEL CLASSIFICATION

J31, J51, C81

ORIGINAL ARTICLE

Five decades of CPS wages, methods, and

union-nonunion wage gaps at Unionstats.com

David A. Macpherson1,2 | Barry T. Hirsch2,3

DOI: 10.1111/irel.12330

Received: 1 August 2022 Accepted: 9 February 2023

INTRODUCTION

There is a rich body of work in labor economics estimating wage differences between union and

nonunion workers in the U.S. The literature on union wage differentials is based heavily on the

work of Lewis(1963, 1986), who provided terminology distinguishing union “gap” and “gain”

differentials. Gap estimates measure wage differences for “similar” union and nonunion workers

and jobs. These wage gap measures are typically obtained from semilog wage equation estimates

based on human capital theory (Mincer,1974). Such equations have been widely used and found

to be empirically robust (Heckman & Polachek,1974).

In contrast to union wage gaps, wage gains reflect the impact of an economy's union density

level (i.e., percent union) on wage levels for both union and nonunion workers. Empirical studies

on wage gains find that wages increase both for union and nonunion workers with respect to

union densities in workers' industries (e.g., Freeman & Medoff,1981) and labor markets proxied

by metro areas (e.g., Holzer,1982). Lewis (1986) was skeptical, concerned that union density

measures may be correlated with wage determinants independent of union effects.

There is a rather vast older literature on unions and union wage gaps. Among those provid-

ing broad summaries of the union literature include Freeman and Medoff(1984), Lewis(1986),

Hirsch and Addison(1986), and Pencavel(1991). Meta-analyses provide considerable support,

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© 2023 The Authors. Industrial Relations published by Wiley Periodicals LLC on behalf of Regents of the University of California

(RUC).