درگیری ها بر سر حقوق مالکیت و بهره برداری منابع طبیعی در مرز

Competition for land at the frontier is analyzed by considering a game between a first settler and a contestant. Although the first settler is the legitimate owner of a plot of land, his remoteness from the government's administrative center makes it difficult to prove it. This creates incentives for a contestant to dispute his claims. Both contenders will expend resources in order to secure ownership. Due to transport costs, the more remote a plot of land is, the lower its output value; this tends to discourage appropriative activities. Land degradation is sometimes used as a substitute to appropriative activities. A lower discount rate may encourage land degradation.

It is a well-documented fact that many tropical forest areas are being subject to unsustainable land-use practices which result in severe land degradation and the permanent loss of forest cover Repetto, 1988, Repetto, 1990 and Barbier et al., 1991. A crucial feature common to most tropical forest areas consists in the fact that they are located far from the markets and the government's administrative centers; for this reason, they are often referred to as “frontier regions.” The purpose of this study is to try to understand how this particular feature of frontier regions can foster the adoption of unsustainable land-use practices. There are many factors suspected to contribute to the state of affairs at the frontiers, as there is often a plethora of agents with various and conflicting interests operating in these regions. In the Brazilian Amazon for instance, Schmink and Wood (1992) list the presence of such diverse types of agents as large ranch and sawmill owners, directors of large mining companies, peasants, wage workers, independent miners, rubber tapers, fishers, Brazil nut collectors, Indians, as well as the many levels of government agencies (federal, state, and local), the military and the police. The authors note the presence of “fundamental contradictions within and between [government] agencies (federal, state, and local)” (p. 15), which testifies that the situation can be a complex one to grasp. There remains, nonetheless, one particularity of frontier settlements which is suspected to have a major impact: it is the presence of tenure insecurity.1 Indeed, one obvious effect of tenure insecurity is to lower the expected value of long-term gains since the settler may have been evicted from the land before these gains have materialized. Hence, the reduced incentives to invest in sustainable land-use practices.2 The mechanics through which ill-defined property rights may encourage an inefficient exploitation of natural resources have been quite extensively investigated, especially in the case of free-access exploitation.3 What has not deserved as much attention in the literature, however, is the fact that incompletely defined property rights may result from a deliberate choice by the exploiter of a resource, who must weigh the benefits of better delineated property rights with its costs.4 Indeed, when the owner of a natural-resource site decides to exploit his site, be it a crop-producing plot of land, a pasture, a fishery, a forest, a hunting ground, or else, he must decide not only on the intensity of exploitation of the resource, but also on the level of expenditures necessary to define and enforce his ownership rights. In the case of natural-resource exploitation, the protection of property rights may take different forms: for example, one requires the exclusion of encroachers who may try to appropriate some of the output from the site, while another involves an outright contest over who actually owns the site. When encroachers are costly to exclude, Hotte (1997) has shown that in order to reduce exclusion expenditures, the exploiter may resort to increasing the intensity of exploitation of his resource. The reason is that a more intensive use of the resource lowers the returns from encroachment. When there is the potential for a contest over a site's ownership, the incumbent may decide to protect his property rights in order to benefit from a long-term, sustained use of the resource. Alternatively, he may decide to deplete the resource, in which case tenure-securing expenditures are reduced since the long-term productive potential of the site has been destroyed, in return for the short-term gains of a quick depletion of the resource's stock. It is the choice between those two alternatives that will be considered in this paper. As mentioned previously, insecure land ownership is particularly prevalent in frontier areas. This situation is explained by the fact that the more remotely located the plot of land is from the government's administrative centers, the less support the settler will receive in the recognition of his land claims, regardless of their legitimacy.5 This opens up the possibility of conflicts, as late comers may try to contest the claims of the first settlers in order to evict them and appropriate the land. The present paper develops a model which is intended to capture the fact that the possibility of an eviction may lead the first settler to adopt an unsustainable use of the land. In doing so, the settler's level of expenditures devoted to the protection of his property rights are endogenized, as well as the level of the contestant's efforts at evicting the settler. In this respect, competition for land is set up as a game between a first settler and a contestant. The analysis proceeds by determining which regime of exploitation and land competition is likely to prevail as the distance from the center varies, taking into account the facts that the government's support in the definition of property rights wears off with distance, while the value of the output decreases due to higher transport costs. The proposed model suggests that the introduction of a positive probability of eviction affects the value of the land in quite the same way as an increase in the discount rate. In one possible scenario, the results indicate that near the center, a settler is most likely to decide to protect his rights of ownership and choose a sustainable use of the land. This is because even though low transport costs confer a high value to the land's output and encourage competition for land, the proximity of government agencies which support the protection of property rights makes it easy for the settler to discourage contestants. As the distance increases, however, he may initially be induced to devote more efforts in protecting his rights of ownership because of the decline in government support. This creates opportunities for conflicts over land and discourages resource conservation. Finally, in more remote areas, competition for land becomes less severe as the output from the land has less value, thus encouraging resource conservation. As will be seen, other scenarios are also possible. The results also indicate that in some cases, a lower discount rate makes it more costly for the settler to protect his rights of ownership. This effect occurs because the lower discount rate contributes to increasing the present value of a sustainable use of the resource. Circumstances under which a lower discount rate, or a higher resource price may foster the adoption of non-sustainable land-use practices are discussed. The paper is organized as follows: Section 2 presents a survey of competition for land as it occurs in various parts of the world. In Section 3, the distance from the center is fixed in order to derive a settler's value function for the land which takes into account the possibility of an eviction. The value function of the contestant's activities are similarly derived. In Section 4, a game of appropriation between a settler and a contestant is proposed in which the arrival rate of an eviction is endogenized. The reaction functions of both contenders are derived as well as the precommitment equilibrium for different values of the parameters. One of these parameters, being the distance from the center, it is shown how these choices may be affected as the distance from the center varies. In Section 5, the choice of a non-sustainable use of the resource is introduced. It is shown how a change in the distance from the center may foster the adoption of non-sustainable land-use practices. A conclusion summarizes the results.

This study has proposed a model of competition for land in frontier regions. These regions were characterized by the fact that due to their remote location, land owners cannot enjoy the strong presence of a legal infrastructure in support of their claims to ownership. As a result, contestants may be tempted to dispute those claims. The owner of the land, however, may respond by devoting resources toward a better delineation of his property rights. On the other hand, as the distance to the centers increases, appropriative activities may be discouraged by the fact that transport costs reduce the value of the land's output. It was seen that as the distance from the center increases, many different scenarios are possible which depend on how fast the price of the resource decreases with distance in relation to the decreasing presence of a legal infrastructure. In one scenario, land owners located near the center protect their rights in such a way as to completely discourage any potential contestant, and the land is used in a sustainable manner. This is due to the strong support of government agencies which are located nearby. A similar equilibrium results at large distances from the center, but in this case, a contestant is not interested in entering into a conflict because transport costs make the value of the output too low to justify appropriative activities. It is at intermediate distances that problems may arise. In one scenario, the land is used in a sustainable way but conflicts take place in which both contenders engage in appropriative activities. In another scenario, no conflict takes place but the land is degraded; in this case, land owners have chosen to deplete the stock of the resource as a substitute to the protection of property rights. Comparative statics suggest that a decrease in the discount rate may, in some cases, encourage land degradation. This is because even though a lower discount rate makes a long-term use of the resource more valuable to land owners, it also encourages more competition over land. The second effect may induce some owners to resort to a depletion of the land's productive potential in order to avoid conflict. More generally, this suggests that any policy aimed at increasing the value of land's output in order to promote conservation should be combined with a better government support for the protection of property rights.