Heterogeneous firms are at the heart of both the New New International Trade Theory and the Micro-econometrics of International Firm Activities. One important aim of micro-econometric studies is to uncover stylized facts that hold over space and time, and that can both inspire theoretical models...

This paper presents a model for the heterogeneity and dynamics of the conditional mean and the conditional variance of standardized individual wages. In particular, a heteroskedastic autoregressive model with multiple individual fixed effects is proposed. The expression for a modified likelihood...