Recent criticisms of the “green revolution” wheats concern the effects of their popularity on crop diversity and the consequences for productivity and conservation. We use a Just-Pope production function to test the relationship of genetic resource and diversity variables to mean and variance of wheat yields in the Punjab of Pakistan. In irrigated areas, greater area concentration among varieties is associated with higher mean yields. In rainfed districts, genealogical variables are associated positively with mean yield and negatively with yield variance. Further research is needed to overcome data limitations, capture biological relationships more accurately, and specify a fuller decision-making model. Copyright 1998, Oxford University Press.

Significance We assess how to meet growing demand for agricultural production to minimize impact on the environment. Higher levels of population and affluence may require expanding land in agriculture by converting grasslands and forests to cropland. Such conversions often reduce valuable ecosystem services. Our research identifies where are the best places to expand agricultural production that minimize the loss of one ecosystem service, carbon storage. We show that selectively choosing where to expand agriculture saves over $1 trillion (2012 US dollars) worth of carbon storage relative to a proportional expansion.

This study examines the existence of a long-run relationship between indigence or extreme poverty reduction and agricultural, manufacturing and tourism development in Costa Rica and Nicaragua. An econometric methodology consisting of an autoregressive distributed lag bounds testing approach to co-integration is used. For Costa Rica, agricultural and manufacturing (not statistically significant) and tourism development are negatively related to indigence poverty with estimated elasticity values of −0.50 for agriculture, −0.17 for manufacturing and −0.58 for tourism. For Nicaragua, the estimated elasticity values are −0.40 for agriculture, −0.13 for manufacturing (not statistically significant) and −0.64 for tourism. Tourism's rate of poverty reduction was statistically significantly greater than that of agriculture for both countries. The main contribution of this paper lies in the understanding of sector contributions to alleviating poverty. The methods utilized can be undertaken by most countries in the world, thereby providing insights into developing targeted investment policies and strategies to achieve higher rates of poverty reduction.

This study shows that the opportunity cost of women's time can affect household food consumption patterns in developing countries. Demand equations for rice, bread, and the ratio of bread to total cereal consumption are estimated for urban Sri Lankan households. The demand specification, which is based on the “New Household Economics,” includes as explanatory variables the woman's estimated market wage and the household's “full income,” and alternatively “observed income.” Wages are estimated using the Heckman procedure to correct for sample selection bias.

This study shows that the opportunity cost of time for husbands and wives can affect the intrahousehold distribution of food in a developing country. Equations which explain the relative allocation of calories within households were estimated for husbands, wives, and children with data for the rural Philippines. The estimating equation is derivable from both a joint household utility function a n d a bargaining model. Because the same households were included in the four survey rounds, the various observations for a given individual were averaged for each variable in the estimation procedure. Wages were estimated using the Heckman approach.