Disparate development occurs in those countries which have within their borders subsidiary subsistence economies or more or less self-contained village societies. This is the situation to a greater or lesser degree in almost every developing country, and it tends to inhibit the growth of manufacturing industry in a number of ways. Within the subsistence sectors-proper, the pre-commercial economic organization practises too rudimentary a degree of division of labour for any industrial specialization to occur. By the same token, a subsistence sector cannot form part of the general market of the country. This insulation of a portion of the population - a very large portion in most African countries, not much smaller in many Asian countries and significant in several Latin American countries - affects economic growth in general but is particularly inimical to the development of secondary industry. It inhibits the flow of labour into occupations requiring industrial skills and keeps off the market a significant proportion of the country's potential purchasers of industrial products.