ABSTRACT
This paper analyzes the founding rate of national labor unions in the United States for the period 1836-1985. It investigates the effects of competitive processes and environmental effects on this rate. A number of stochastic models embodying different assumptions about the ecology of foundings are estimated. The best-fitting models posit that the effect of density (the number of unions in existence) and the number of recent foundings on the founding rate is curvilinear. Analysis of more complicated models reveals that the growth of industrial unions inhibited the founding rate of craft unions. However, the founding rate of industrial unions was unaffected by the number of craft unions in existence.
