Economists have produced a sizable literature examining the role of labor migration in restoring wage and price equilibria among dispersed markets. A much smaller literature addresses another dimension of mobility, regional migration of entrepreneurs and firms. In this study we examine a model of the firm's decision to migrate, utilizing the Duns Market Identifiers data file. The model consists in part of an equation describing the decision to migrate, in order to determine the extent to which measured characteristics of the firm's environment explain firm migration. Additional equations in the model explain particular outcomes of migration: the growth in sales during a fixed interval after a move and the corresponding growth of employment. Copyright © 1987, Wiley Blackwell. All rights reserved