The Complexity of the Commons: Environmental Resource Demands in Rural Zimbabwe

The literature on the relationship between households and environmental change commonly termed the poverty-environment relationship is characterised by theoretical inadequacies and a lack of empirical verification. In this paper, we start by presenting a model which integrates a multiple-use environmental resource system within the standard agricultural household model. We demonstrate the theoretical importance of examining the way in which multifarious environmental goods interact with the household’s other production and consumption decisions. Environmental goods are significantly differentiated in economic terms, so that environmental resources can be affected very differently by changes in an exogenous parameter such as income, prices, household structure, resource availability, technology and so on. It is this that endows the commons with its complexity: the range of environmental resources is wide and the set of possible responses by each resource to perturbations is large, so that characterising the poverty-environment relationship in terms of a single function, as is so often done, is wholly inadequate. We then turn to empirical analysis using an analysis of cross-sectional demand functions for environmental goods, using a purpose-collected data set from 29 villages in Shindi Ward, Chivi District, south-eastern Zimbabwe. We find that the econometric results from these environmental demand regressions support the theoretical conclusions. Estimated income elasticities differ across goods and species, and there is clear evidence that other demand determinants such as species substitute and backstops, scarcity and household structure also affect different goods in different ways. We also examine the case study literature on rural households’ resource use in Zimbabwe: this demonstrates that both environmental demands and environmental supplies are affected by a number of different factors. So we suggest that the commons is a complex place: environmental resource use and hence also environmental change will be driven by a multiplicity of factors, and these factors can differ quite considerably across different species and resources. Simplistic conceptions of the link between rural households and the environment will be quite wrong. Indeed, Dasgupta reflects this concern: “There has been a parallel weakness in academic economics on matters 1 concerning the environmental resource base of rural production. The dependence of poor countries on their natural resources, such as soil and its cover, water, forests, animals and fisheries, should have been self-evident. Nevertheless if there has been a single thread running through 40 years of investigation into the poverty of poor countries, it has been the neglect of this base.” (p273).