According to sustainable livelihoods research, diversity (i.e. the exploitation of multiple assets and sources of revenue) is an intrinsic attribute of many rural livelihood strategies. This assumption is consistent with findings of anthropological studies on the household economy of pre-industrial peasant societies, as well with the concept of integration which (along with participatory methods) inspires the farming system approach. Indeed, until the beginning of the development era, the majority of rural population in both developed and developing countries has survived and reproduced by growing a mix of staple and cash crops, keeping some livestock, fishing, and gathering forest products. Subsistence production, aimed at meeting food needs, combined with selling of small surpluses on the local market (including often labor surpluses). The latter was instrumental to access the manufactured goods and other commodities that can not be produced by the household, as well as to pay taxes and ceremonial expenses (Wolf 1966). Following some insights that Russian agronomist A.V. Chayanov developed in 1920s and 1930s (Chayanov 1966), anthropologists tend to agree that such diverse production patterns were instrumental to the attainment of the basic economic goals of pre-industrial rural households: maintenance of consumption standards, creation of conditions for future reproduction and avoidance of drudgery (Sahlins 1972; Scott 1976).
Though pockets of people practicing the pre-industrial mode of production may continue to exist in remote areas of the world, this livelihood strategy has entered during the last fifty years into major straits. Well known driving factors of this crisis include:
population growth and the subsequent progressive shrinking of land holdings size and environmental degradation;
the incorporation of rural areas into national markets and the increased vertical integration of farmers household in national economy;
the subsequent decrease of the relative importance of small farmers as producers of agricultural commodities, due to the expansion of capital intensive agriculture and globalization of the world food market;
the growing (though somehow erratic) demand for both agricultural and industrial wage labor;
the massive diffusion of new agricultural technologies and of transport/communication facilities;
structural readjustment policies which decreases the availability of public support to small-scale agriculture and often make access to new technologies and information less affordable to small farmers;
the emergence among rural people of new social needs (education, modern health care, technological commodities);
the increasing importance of cash transactions in rural household economies that all the above imply.
Under the thrust of this major evolutionary process and following the appeal of modernizing policies aimed at integrating the rural areas in the mainstream of national society and economy, during the on going development era, rural people have been urged to progressively re-arrange their traditional livelihood portfolio. Activities no longer economically and socially viable have been replaced with new ones better suiting the context of a more mature market economy. Moreover, industrial organizational patterns (such as, contract farming) have been introduced into the rural household economy, giving often birth to hybrid livelihood strategies.
 According to DFIDs
sustainable livelihoods glossary the term livelihood strategies denotes:
the range and combination of activities and choices that people make in
order to achieve their livelihood goals. Livelihood strategies include: how
people combine their income generating activities; the way in which they use
their assets; which assets they chose to invest in; and how they manage to
preserve existing assets and income. Livelihoods are diverse at every level, for
example, members of a household may live and work in different places engaging
in various activities, either temporarily or permanently. Individuals themselves
may rely on a range of different income-generating activities at the same
time (DFID 2001).|