The forthcoming enlargement of the European Union (EU). Which will encompass, among others, ten Central and Eastern European countries, is both an opportunity and a challenge of unprecedented proportions. This project consists on analyzing how both the European Union (EU) and Central and Eastern European Countries (CEEC's) should prepare for, and successfully undertake, European Union enlargement. The research will be centred on one dimension of the EU enlargement towards the East of Europe that have received less attention in the economic literature: the CEEC'S can profit from the Spanish experience, taking into account that there are similar characteristics between these countries and Spain before its adhesion. Thus, the research project will analyze the relative structural costs that candidate countries will probably support, comparing the economic situation of these countries with that of Spain prior to its adhesion. The results of the research will be used in a seminary on EU enlargement and will be included in a web page entirely devoted to this topic. Besides, the co-operation between the CUREI and a professor of a well-known Spanish university will foster intra-Europe scientific dialogue on compared political and economic issues. The variety of the available supervisors within the CUREI staff and the interdisciplinary composition of the groups. allow to introduce the applicant into other fields, like political science and law, very connected with the project.