This book is the result of five years of research that I carried out as a research fellow at the Faculty of Economics and Econometrics of the University of Amsterdam. The project was initiated in 1986 by Frans van Winden and Roy Thurik. Frans van Winden became interested in self employment through his work concerning government behavior. In the models that he employs, the government is influenced by various social groups, the political strength of which is related to their size. As one of these is the group of self-employed individuals, he became interested in determinants of the size of this...