capital flows in ways that produce shifting landscapes of production, consumption, and vulnerability (Liverman, 2008).
Differences in wealth and poverty are often not solely the result of local circumstances; they are produced by relationships that link far-flung places. Geographical scientists investigate how spatial relationships shape inequality, such as the relationships between production in low-income countries and rich-country consumption, or the inequality effects of deploying agricultural lands for domestic foodstuffs or for export crops. They have developed conceptual and analytical tools for tracing the networks of production, consumption, and exchange that link people across world markets and for identifying the processes through which wealth and poverty are explicitly linked. Of particular significance is work on (1) production chains—linked sequences of place-based functions where each stage adds value to the commodity (Dicken, 2007); (2) consumption chains—links between consumption and the conditions of production (Hartwick, 1998); and (3) global commodity chains, which expose prices, and the geographical distribution of value, at each node along the production and marketing trajectory of a specific commodity (Gereffi and Korzeniewicz, 1994; Leslie and Reimer, 1999).
Geographical research on commodity chains is enchancing understanding of the ways in which inequality is reworked through production and consumption linkages. For example, Nepstad et al. (2005) have traced how consumers in high-income countries shape the nature of agricultural commodity chains through an examination of the globalization of soy and beef industries based in the Brazilian Amazon. They developed a network analysis that connects growing fears of bovine spongiform encephalopathy (BSE or mad cow disease) in ration-fed beef in the United States and Europe with increasing demand for grass-fed beef from the Amazon. Their work demonstrates how conditions of production are reworked by pressures from consumers demanding both improved environmental stewardship and better social conditions for workers. Their study reveals that pressures from lender and consumer organizations to reduce the negative socioecological impacts of production are leading to the environmental and social certification of beef, timber, and soybeans. Additional geographical research building on this conceptual and empirical foundation could further elucidate the nature of commodity networks and show how certification