It is difficult to draw conclusions about the nutritional implications of a particular portfolio of research activities because the sources of nutritional impacts identified above can act counter to one another. For example, a labor-saving technology used to produce export crops might lower wages and not induce changes in food supply, thus making landless laborers worse off. Some concern has been voiced about the nutrition effects of research devoted to export-crop production. If
numerous producers switch from food crops to export crops, then there is potential for domestic food prices to rise, and such a rise would hurt the urban and landless poor. However, there is little empirical evidence of this switch, and nutritional levels are perhaps most influenced by research that generates the largest income gains, particularly if those
gains are realized by low-income producers. Therefore, focusing research disproportionately on commodities with high nutritional content may result in less income than if the research were focused on other commodities. For example, improving the productivity of a vegetable export crop in Guatemala may improve the family’s nutrition more than
improving the productivity of its maize crop, because the former will lead to a greater increase in farm income and therefore the family’s ability to buy food.