A Lagrange multiplier test for the mean stationarity assumption in dynamic panel-data models

In this article, we describe the xttestms command, which implements the Lagrange multiplier test proposed by Magazzini and Calzolari (2020, Econometric Reviews 39: 115–134). The test verifies the validity of the initial conditions in dynamic panel-data models, which is required for consistency of the system generalized method of moments estimator.