Gergő Medve-Bálint's research data about the regional development and inequalitites in Visegrád countries are now available in the RDC's reporitory. The researcher concludes that the EU-incentives that have been implemented concerning investments and the regional developmental policies have -- contrary to their aim -- not reduced, but raised the regional inequalities among the Visegrád countries. The collection contains the longitudinal data of the four countries, among others about the state-funded foreign investments and the EU structural funds.