In my dissertation I seek to shed light on the divergent economic paths of Mexico and Spain in the second half of the 20^th Century. Throughout their modern histories these economies showed striking similarities in performance, structural constraints and institutions. Based on a historical analysis based on economic, political, intellectual and demographic theory, I argue that Mexico fell behind Spain due to structural and conjunctural factors that appeared or became relevant only during the 20^th Century. These factors can only be explained taking into account not only economic trends, but including political, demographic and intellectual developments.

The chapters in the first section follow an analytical approach in order to describe the unequal performance of Latin America and Europe in general, and of Mexico and Spain in particular. The first chapter reviews the long-term tendencies of both regions to identify two different trends: interregional economic divergence and intraregional economic convergence. The second chapter focuses on the analysis of Mexican and Spanish economic history in order to demonstrate the relevance and viability of this comparison, and to explore a few hypotheses, particularly those related to demographic trends and economic policy-making. Chapters three and four deal with demography in Mexico and Spain from two very different perspectives. First, a quantitative approach is taken, to try to seek out an explanation for such different demographic behavior in two countries with many historical, cultural and institutional similarities. Second an intellectual history of demographic analysis and policies, based on both secondary and primary sources, shows the inability of both regimes to deal with the demographic question effectively. The final chapter deals with the political economy of development in both countries. It explains the differences in the timing and speed of economic reforms in Mexico and Spain. The chapter suggests an institutional explanation for the fact that Spain had more political flexibility to adapt its economic policies to international market conditions. In addition, this explanation goes beyond the most common institutional arguments, and attempts to explain the origin of these institutional differences.