Models for the Analysis of Labor Force Dynamics

This paper presents new econometric methods for the empirical analysis of individual labor market histories. The techniques developed here extend previous work on continuous time models in four ways: (1) A structural economic interpretation of these models is presented. (2) Time varying explanatory variables are introduced into the analysis in a general way. (3) Unobserved heterogeneity components are permitted to be correlated across spells. (4) A flexible model of duration dependence is presented that accommodates many previous models as a special case and that permits tests among competing specifications within a unified framework. We contrast our methods with more conventional discrete time and regression procedures. The parameters of continuous time models are in- variant to the sampling time unit used to record observations. Problems plague the regression approach to analyzing duration data which do not plague the likelihood approach advocated in this paper. The regression approach cannot be readily adopted to accommodate time varying explanatory variables. The functional forms of regression functions depend on the time paths of the explanatory variables. Ad hoc solutions to