不同承诺能力下可耗竭资源的最优消耗

The Optimal Depletion of Exhaustible Resources Under Different Commitment

通过对可耗竭资源经济学的文献回顾,目前尚没有发现在可变时间偏好理论框架下探讨可耗竭资源的最优消耗等问题。该文尝试在双曲线贴现的可变时间偏好下,对一个可耗竭资源的纯消耗问题进行分析,讨论在不同承诺能力下资源的最优消耗速度及对资源的保护效果。模型结果证明,在国家的完全承诺能力下,资源的最优消耗速度最慢,选择的初始资源消耗最低,与时间偏好不变情况下的社会计划者问题等价。相反,在完全无承诺能力下,资源的最优消耗速度最快,选择的初始资源消耗最高,其短视的资源消耗行为必然会导致可耗竭资源的过度消耗。部分承诺能力下的情况则介于完全承诺能力情况与完全无承诺能力情况之间。因此,在双曲线贴现的时间偏好下,资源消耗的最优速度依赖于承诺能力,承诺能力的提高会导致更低的有效时间偏好率,从而导致更低的资源消耗速度和初始资源消耗。承诺技术纠正了人们的不耐心程度与短视行为,从而达到保护可耗竭资源的目的。

There is yet no literature focusing on the issue of the optimal dephetion of exhaustible resources in the fromework of variable time preference. This paper attempts to analyze pure consumption of exhaustible resources under hyperbolic time preference, and to discuss the optimal depletion rate and the effect of the protection of exhaustible resources under different commitment abilities. The results of the model show that the case of the hyperbolic discount with the full commitment of the eountry is equivalent to the case of constant discount of the social planner problem. In this case, the optimal depletion rate and the initial consumption of exhaustible resources are the slowest. On the eontrary, they are the highest and the near-sighted behaviors inevitably lead to excessive consumption of exhaustible resources without commitment. Besides, in the case of partial commitment, the results are between the cases of full commitment and those of no commitment. Therefore, with the hyperbolic time preference, the optimal depletion rate of resources depends on the commitment ability. Higher commitment ability leads to lower effective rate of time preference, and consequently, lower depletion rate and lower initial depletion value. The improvement of commitment ability can decrease men＇ s impatience and nearsighted behaviors, and contribute to the protection of exhaustible resources.