In Italian historiography, the southern question is the perception, dating back to the aftermath of the unification of Italy, that southern Italy is persistently backwards in terms of socioeconomic development compared to the other regions of the country, especially the ones in northern Italy. First used in 1873 by Lombard classical radical and Historical Far Left deputy Antonio Billia, meaning the disastrous economic situation of the south of Italy compared to other regions of united Italy, it is used in common parlance even into the 21st century. The great southern emigration began only a few decades after the unification of Italy, where in the first half of the 19th century it had already affected several areas in the north, particularly Piedmont, Comacchio, and Veneto. The historical reasons for the first southern emigration in the second half of the 19th century are to be found in widespread literature both in the crisis of the countryside and grain, and in the situation of economic impoverishment affecting the south in the aftermath of unification, when industrial investments were concentrated in the northwest, as well as in other factors.