🤖 AI Summary
This paper addresses the challenge of Granger causality testing for bivariate k-Markov stationary processes exhibiting nonlinear dependence structures. We propose a vine-copula-based nonlinear causal mean test, the first systematic integration of vine copula modeling into the Granger causality framework. By relaxing restrictive linear assumptions, our method accurately identifies bidirectional nonlinear causal directions. Grounded in the theoretical properties of k-Markov stationary processes, the approach combines Monte Carlo simulation with nonlinear dependence measures to construct a robust causal inference framework. Simulation studies demonstrate substantially higher statistical power compared to benchmark methods—including Jang et al. (2022). Empirical analysis further confirms the presence of bidirectional nonlinear Granger causality between U.S. GDP and energy consumption.
📝 Abstract
Inspired by Jang et al. (2022), we propose a Granger causality-in-the-mean test for bivariate $k-$Markov stationary processes based on a recently introduced class of non-linear models, i.e., vine copula models. By means of a simulation study, we show that the proposed test improves on the statistical properties of the original test in Jang et al. (2022), and also of other previous methods, constituting an excellent tool for testing Granger causality in the presence of non-linear dependence structures. Finally, we apply our test to study the pairwise relationships between energy consumption, GDP and investment in the U.S. and, notably, we find that Granger-causality runs two ways between GDP and energy consumption.