The influence of technological opportunity on union membership in U.S. manufacturing industries

I examine influences of technological opportunity on a set of factors determining inter-industry variation in union membership density. A data set of 239 U.S. manufacturing industries is divided into subsets of “technologically progressive “ and “technologically unprogressive “ industries, and my unionization model is estimated for each subset. The study confirms recent findings indicating that innovation activity and industry concentration have significant negative effects on union membership density. However, these results are obtained only for the subset of “technologically progressive industries and not for the “technologically unprogressive “ industries. These findings suggest that estimation bias is imparted to interindustry studies of the extent of union membership through the influence of technological opportunity on the interrelationships between innovation output, industry concentration, and union membership density.