Habitat conservation, wildlife extraction and agricultural expansion

Abstract

We develop a model of open access wildlife exploitation, habitat conservation and agricultural expansion, which is consistent with rural communities at the fringe of natural habitats in areas such as sub-Saharan Africa. Farmers have the option of either hunting for wildlife or growing crops. The opportunity cost of each activity is the return to the other (economic interdependence), and habitat conversion affects the returns to both activities (ecological interdependence). We show how different patterns of conservation and agricultural expansion may emerge, and that greater conservation may be consistent with higher incomes. We also show that wildlife stocks under open access may be greater than wildlife stocks under a common property (or social planner's) regime.

Introduction

Wildlife is threatened by many factors, of which habitat conversion to other uses (such as agriculture and urban development) and human (over) exploitation are best known and most notorious. According to the World Conservation Monitoring Center [42], of 486 documented extinctions since 1600, 80 have resulted from hunting and 98 have resulted from habitat destruction. Over-exploitation, usually combined with habitat destruction, is believed to threaten about one-third of the world's endangered mammals and birds.

Interestingly, wildlife exploitation and habitat conversion choices differ significantly across societies so that the worldwide distribution of “nature” varies considerably. Some countries host the bulk of nature and biodiversity whereas others have converted their natural assets in the past or are currently doing so [42]. Consider recent land use developments in Kenya and Southern Africa as an example. Child [10] concludes “Kenya's wildlife is in trouble” whereas wildlife “thrives” in Southern Africa. In less than 20 years, private South African land allocated to wildlife has increased from 1 to 8 million hectares (compared to 2.8 million hectares controlled by the National Parks Board). In Kenya, during the same period, wildlife was excluded from large areas of its traditional habitat to minimize competition for forage with livestock and to protect and promote the expansion of arable agriculture [25]. As a result, Kenyan herbivore populations have declined by 40–60% since 1977 while South African wildlife populations have increased. A number of factors contribute to these differences in conservation choices, including differences in population pressures [35], property rights and use rights for land and wildlife resources [9], and fiscal policies—particularly those promoting agricultural expansion [28]. However, conservation choices differ even in societies with similar property rights regimes and agricultural expansion policies. It is important to understand why this may occur, particularly in less developed regions where property rights are ill defined and conversion of “nature” is an important issue.

South African experiences suggest that wildlife exploitation and conservation efforts do not necessarily conflict. Indeed, allowing (local) people to utilize wildlife as a renewable resource may trigger incentives to carefully manage wildlife as a valuable asset and to allocate scarce land to its survival. The so-called integrated conservation and development projects (ICDPs) are based on this notion and are financially supported by hundreds of millions of dollars by organizations such as the World Bank [3]. ICDPs are increasingly promoted to encourage communities on the periphery of natural habitat to sustainably harvest wildlife, possibly in return for alternate sources of income or sustenance. Barrett and Arcese [3], [4] critically assess the potential long-run benefits of such programs, concluding that the design of ICDPs over the past decade leaves much to be desired.

This paper contributes to the understanding of development policies and wildlife conservation by explicitly modeling the role of habitat and spillover benefits. One objective is to investigate why, under conditions of ill-defined property rights for habitat and wildlife resources, some societies preserve wildlife at the expense of agricultural expansion, while others expand agricultural lands at the expense of conservation. We find that multiple equilibria may lead to an outcome with little habitat and wildlife or, in contrast, with little agricultural conversion and abundant wildlife stocks.¹ In particular, we find conservation choices may be driven by spillover effects that are somewhat analogous to those of the “big push” literature in development economics (e.g., [22]). We identify situations in which a “little pull” can encourage conservation and increase economic well being by creating backward and forward linkages in the wildlife sector that promote economic expansion. This can be interpreted as theoretical support for ICDPs and for the efforts of organizations such as Africa Resources Trust to promote wildlife utilization by local people.

Another objective is to investigate the effects of conservation and agricultural expansion policies when property rights remain ill-defined. For example, trade measures to promote wildlife conservation may achieve the opposite result, depending on the particular steady state that the system is in. We also find that ill-conceived domestic policies to expand agriculture may make everyone in the economy worse off. Accordingly, conservation and development policies should be jointly considered and implemented with great care.

Finally, we evaluate the often-heard claim that lack of property rights is a major cause of excessive resource depletion. We compare wildlife stocks under conditions of open access and cooperative common property management, finding that open access stock levels may exceed socially optimal levels. Thus, it is too simple to equate ill-defined property rights with over-exploitation. We are not familiar with existing literature arriving at this conclusion.