Do Spanish regions converge? : A time-series approach using fractional cointegration

This article investigates economic convergence in terms of real income per capita between the autonomous regions of Spain over the period 1955–2020. In order to converge, the series should be cointegrated. This necessary condition is checked using two testing strategies recently proposed for fractional cointegration, finding no evidence of cointegration, which rules out the possibility of convergence between all or some of the Spanish regions. As an additional contribution, an extension of the critical values of Nielsen’s (2010) test of fractional cointegration is provided for a different number of variables and sample sizes from those originally provided by the author, fitting those considered in this article.