Research results are our tool for approaching reality and truth. Validity and reliability of research instruments is the gate to reach generalizable results. The validity and reliability of an instrument are important aspects that allow for using the instrument in future research. This study...

The random parameters logit model for aggregate data introduced by Berry, Levinsohn, and Pakes (1995) has been a driving force in empirical industrial organization for more than a decade. While these models are identified in theory, identification problems often occur in practice. In this paper...

This paper develops a general theory of instrumental variables (IV) estimation that allows for both I(1) and I(0) regressors and instruments. The estimation techniques involve an extension of the fully modified (FM) regression procedure that was introduced in earlier work by Phillips-Hansen...