Wages,union membership,and public sector bargaining legislation: Simultaneous equations with an ordinal qualitative variable

A simultaneous equations model of teachers’ wages and unionization is constructed. The exogenous impact of collective bargaining legislation is captured by conditioning the wage-union system on an ordinal qualitative variable. A new estimation method involving N-chotomous probit and two-stage least squares is developed. The estimation results are consistent with a private interest theory of regulation, predicting that legislators will avoid direct subsidization of teacher wages. By comparison it is also shown that a conventional dummy variable specification of the qualitative legislative outcomes will yield misleading results. The authors gratefully acknowledge the helpful comments of John Addison, Cletus Coughlin, and Robert P. Trost.