🤖 AI Summary
This study addresses the challenge of non-nested model selection in panel data settings involving individual-by-time fixed effects, where the conventional Vuong test fails due to the lack of regularity in the standard profile likelihood. By introducing a modified profile likelihood combined with the Kullback–Leibler information criterion, this work extends the Vuong test for the first time to a generalized panel data framework, effectively overcoming the technical obstacles posed by fixed effects. The proposed method delivers a rigorous and computationally feasible statistical inference tool for linear panel models featuring non-nested specifications of individual–time interaction effects, thereby substantially broadening the applicability of non-nested hypothesis testing in panel data analysis.
📝 Abstract
This paper generalizes the classical Vuong (1989) test to panel data models by employing modified profile likelihoods and the Kullback-Leibler information criterion. Unlike the standard likelihood function, the profile likelihood lacks certain regular properties, making modification necessary. We adopt a generalized panel data framework that incorporates group fixed effects for time and individual pairs, rather than traditional individual fixed effects. Applications of our approach include linear models with non-nested specifications of individual-time effects.