7 Fuzzy Access: Modeling Grazing Rights in Sub-Saharan Africa

In Sub-Saharan Africa, mobility through transhumance is a much-valued strategy of pastoralists for dealing with rainfall variability (see Swallow 1994; van den Brink, Bromley, and Chavas 1995; Ellis and Swift 1988). Transhumance is generally practiced in the arid to semi-arid regions of Sub-Saharan Africa, an environment characterized by low mean rainfall and high rainfall variability. Higher rainfall variability increases the value of access to larger grazing areas and the concomitant ability to adjust to weather shocks after the fact, provided that rainfall is not perfectly correlated for all areas (Thompson and Wilson 1994). However, spatial mobility and grazing access are costly. Migration imposes human labor costs as well as the cost of the energy used by the animal for migrating. Transaction costs are also associated with mobility; some form of transacting must take place among the varying pastoralist groups to govern access to pasture resources (van den Brink, Bromley, and Chavas 1995; Swallow 1994). As clearly shown in van den Brink, Bromley, and Chavas (1995), if land quality and mean rainfall are sufficiently low and rainfall variability is sufficiently high, some type of nonexclusive property right will dominate privatization even when transaction costs of mobility are introduced, although their model assumes socially optimal use of the nonexclusive rangelands. Thus, the introduction of spatial rainfall variability into the analysis of rangeland management systems provides economic support for leaving large tracts of land open to common grazing. On the other hand, land resources held in common are still subject to the possibility of overuse when management of these resources is not perfect. Van den Brink, Bromley, and Chavas (1995) argue that traditional authorities had been (and in some cases, may still be) capable of coordinating access to pasture and water resources, and that a well-defined membership obeyed rules and regulations over use of these resources. The existence of the traditional land-access institutions would theoretically mitigate the negative externalities generally associated with unregulated common-property resources. Accordingly, their analysis does not consider possible negative externalities that arise under imperfectly managed common property. There are a number of reasons for examining more closely the case in which these common grazing lands are not managed perfectly. Within the livestock sector, Jarvis (1980) dis cusses evidence that suggests that the communal nature of the grazing system used in Swaziland is a crucial determinant of pas