Comparisons Between Public and Private Sector Union Wage Differentials: Does the Legal Environment Matter?

A stylized fact in the growing literature on public sector labor markets is that estimates of public sector union wage premia are significantly lower than estimates of private sector union wage premia. In this paper I investigate the hypothesis that this difference may in part be due to the differing legal environments in which public and private sector unions operate. Using data from the Current Population Survey and the Census of Population, I find that public sector union wage differentials increase significantly with the degree of legal protection afforded to the union in bargaining. However, the estimated public sector union wage premia when no legal controls are included in the specification are close to the estimated premia under the strongest legal environment. Consequently, while controlling for the legal environment in the public Sector is important, it may not reconcile the differences between estimated public and private sector union wage premia.