The major problem in rural Greece is it depopulation. From 1961 to 1971 the urban population of Greece increased from 43.3 to 53.2 percent, while at the same time its rural population decreased from 43.8 to 35.1 percent. This movement away from farming has reached very high levels in some poor and distant regions of the country. Mani, located on the extreme southern part of continental Greece, is such a region. The urbanization movement, resulting mainly from the lower returns to labor employed in farming, as compared to that employed in most non-farm occupations and from the centralization of industry in the bigger urban centers has resulted in accumulating population near Athens and Salonica, (in 1971, the population of Athens proper was 29.0 percent of the whole country). This concentration, in combination with the country's adverse physical conditions, which limit the substitution of labor for capital in farming, has caused important questions about the demand for and supply of farm products. Various suggestions have been made for decreasing out-migration. Some people argue that a change in crop patterns of some regions and reallocation of their productive resources could achieve a substantial increase in the farm incomes and thus stop or decrease the depopulation. Others believe that the key is the decentralization of industry to increase employment in the rural areas.