In part I of this book a dynamic migratory model connecting the microlevel of individual migration trends with the macrolevel of interregional migration is developed. Its derivation makes use of the master equation method. Applying a ranking regression analysis, the trend parameters of the model are correlated to regional socio-economic key factors. In part II the model is applied to interregional migration within the countries Federal Republic of Germany, Canada, France, Israel, Italy and Sweden. In part III a comparative analysis of the results is given. In part IV a selfcontained derivation of the master equation and of solutions relevant for the migratory system is given, the ranking regression analysis is exemplified and a computer program for the estimation of trendparameters is added.