This paper studies the evolution of Spanish regional inequality from 1860 to 2000. The results point to the coexistence of two basic forces behind changes in regional economic inequality: differences in economic structure and labor productivity across regions. In the Spanish case, the initial expansion of industrialization during the period 1860-1900, in a context of growing economic integration of regions, promoted the spatial concentration of manufacturing in certain regions, which also benefited from the greatest advances in terms of labor productivity. Since 1900 and until 1985, the diffusion of manufacturing and services production to a greater number of locations generated the emulation of production structures and a process of catching-up in labor productivity and wages. So, in these first 125 years, national market integration and economic growth has been followed by a Ushaped evolution of regional incomes inequality. Nevertheless, some productivity differentials remained and, from 1985 on, the Spanish entry in the UE generated a new upsurge of divergence in productivity across Spanish regions that could be in the base of a new phase of regional income divergence
