Two Aspects of Labor Mobility: A Bivariate Poisson Regression Approach.

The study introduces a distinction between two types of labor monthly. Direct job-to-job changes (which are assumed to be voluntary) and job changes after experiencing an unemployment spell (assumed to be involuntary). Exploiting the close relationship between those two phenomena, we adopt a bivariate regression framework for our empirical analysis of data on male individuals in the German labor market. To account for the non-negative and discrete nature of the two counts of job changes in a ten year interval, a new econometric model is proposed: the Bivariate Poisson regression proves to be superior to the univariate specification. Further, the empirical content of distinguishing between two types of mobility is subject to a test, and in fact, supported by the data: The hypothesis that both measures are observationally equivalent can be rejected.