This paper studies semiparametric versions of the classical sample selection model (Heckman (1976, 1979)) without exclusion restrictions. We extend the analysis in Honor'e and Hu (2020) by allowing for parameter heterogeneity and derive implications of this model. We also consider models that...

Two of Peter Schmidt's many contributions to econometrics have been to introduce a simultaneous logit model for bivariate binary outcomes and to study estimation of dynamic linear fixed effects panel data models using short panels. In this paper, we study a dynamic panel data version of the...

This paper investigates the construction of moment conditions in discrete choice panel data with individual specific fixed effects. We describe how to systematically explore the existence of moment conditions that do not depend on the fixed effects, and we demonstrate how to construct them when...

The purpose in this paper is to summarize existing evidence on welfare dependence among immigrants in Denmark and to supply new evidence with focus on the most recent years. Focus is on immigrants from non-western countries. The paper contains an overview of the background regarding immigration...

The purpose in this paper is to survey the course of immigration into Denmark and research and studies related to the problems encountered in this area. The first part of the paper describes the actual flows of migrants in the most recent decades. The directly job-related part of migration can...