“…More frequently, studies conclude that additional work is needed to better understand this link. Lack of data has influenced study results of, for example, Enamorado, López-Calva and Rodríguez-Castelán [2014]. Analysis of the date that is available relies on the panel data or time series methods [Burnham et al, 2004;Mauro, Carmeci, 2007;Pan, Widner, Enomoto, 2012;Kumar, 2013;Goulas, Zervoyianni, 2013;Enamorado et al, 2014].…”