Related and unrelated variety and convergence to technological frontier: empirical evidence for Polish regions

This paper examines the effects of related and unrelated variety on total factor productivity (TFP) in Poland. Based on dynamic panel data regression results for Polish regions in 2003-2019, we find the positive effect of related variety and the strong negative effect of unrelated variety on TFP. This implies that regions with high related and low unrelated variety optimize TFP. Using the estimated TFP values, we tested for TFP convergence to the technological frontier using convergence tests that take into account significant differences in technological advancement across regions. We reject TFP convergence for all regions, but we find evidence of regional club convergence. The results of the convergence tests obtained for the simulation variants indicate that changes in related and unrelated variety structures may lead to the formation of convergence clubs with the regional technological leader. Furthermore, the changes primarily in related variety structures lead to the convergence of some regions to the regional technological frontier.