In this paper we introduce fixed-T unit root tests for panel data models with serially correlated and heteroscedastic disturbance terms. The tests are based on pooled least squares estimators for the autoregressive coefficient of the AR(1) panel model adjusted for their inconsistency. The...

This paper considers estimation of panel data models with fixed effects. First, we will show that a consistent ``unrestricted fixed effects'' estimator does not exist for autoregressive panel data models with initial conditions. We will derive necessary and sufficient conditions for the...

In this paper we consider inference procedures for two types of dynamic linear panel data models with fixed effects. First, we show that the closure of the stationary ARMA panel model with fixed effects can be consistently estimated by the First Difference Maximum Likelihood Estimator and we...