基于最优轮伐期模型的超限额采伐现象及其约束机制分析

文中将最优轮伐期模型应用于对超限额采伐现象的研究,认为由于国有森工企业的利润大多来自于木材销售收入,而企业领导的任期是有限的,他们只关心自己任期内的业绩,导致企业经营的目标实际上是短期木材收益的最大化,而不是我们所期待的可持续木材与生态综合收益最大化,甚至也不是私人拥有森林时所追求的长期木材收益的最大化。他们会设法突破政府设定的采伐限额,增加采伐量,造成森林资源加速衰退的不良后果,不仅生态功能迅速萎缩,木材产量也无法长期维持下去。同样的情形在国有林场短期租赁给私人经营时也极易发生。为尽量杜绝这种现象,有必要通过建立有效的监督和惩罚机制使超采所带来的额外收益小于被发现时上缴罚款的数学期望值,以此从根本上遏制住企业超限额采伐的动机。

Analysis to Over-the-Quota Harvesting and Its Constraint Mechanism Based on Optimal Harvesting Decision Model

The paper analyzes the over-the-quota harvesting phenomenon using the optimal harvesting decision model, and it is concluded that state-owned forestry enterprises obtain the profit mainly from the timber revenue while the enterprise leaders only have limited office term, and this situation leads to the consequence that they only care for the achievement during their office term and the maximized short-term timber revenue instead of maximized long-term cash flow of the timber and environmental revenue as expected and even the maximized long-term timber revenue which is often pursued by the private forest owners. Thus these state-owned forestry enterprises may always try to harvest more beyond the quota set by the government. Their actions accelerate the deterioration of forest resources, not only causing shrunken environmental functions, but also unable to sustain the timber production. Such phenomenon occurs often when the government rent out the state-owned forest to private operators for short-term management. In order to stop this phenomenon, it is necessary to set up effective supervising and punishing mechanism to make the extra profit brought by over-the-quota harvesting less than the mathematical expectation of the fine decided once detected, for keeping down the enterprises' motivation to harvest beyond the quota.