© The Author 2014. The article presents and discusses estimates of social and economic indicators for Italy and its regions in benchmark years roughly from Unification to the present day: life expectancy, education, gross domestic product (GDP) per capita at purchasing power parity, and the new Human Development Index (HDI). A broad interpretative hypothesis, based on the distinction between active and passive modernization, is proposed to account for the evolution of regional imbalances. In the lack of active modernization, Southern Italy converged thanks to passive modernization. However, this was more effective in life expectancy, less successful in education, expensive, and as a whole ineffective in GDP. As a consequence, convergence in the HDI occurred from the late nineteenth century to the 1970s, but came to a sudden halt in the last decades of the twentieth century.