Optimal Harvesting of Timber: Valuing Timberland with Stochastically Evolving Timber Volume and Prices Using Linked Biological/Geographical Data from British Columbia

木材的最佳采伐：利用不列颠哥伦比亚省的相关生物/地理数据，通过随机变化的木材数量和价格来评估林地价值

• 批准号: 0241509
• 负责人: John Rust
• 金额: $ 21.94万
• 依托单位: National Bureau of Economic Research Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-07-01 至 2007-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0241509&HistoricalAwards=false
• 关键词: Optimal; Harvesting; Timber; Valuing; Timberland

In environmental and natural resource economics, the management of renewable natural resources is of considerable interest to economists because the prospect of stewarding a resource forever has practical importance and real-world relevance. Moreover, because past failures in managing certain renewable natural resources properly have lead to the extinction of several species, developing practical strategies for managing remaining renewable natural resources is both timely and useful. This project investigates in detail the management of one renewable natural resource, timber, in the province of British Columbia, Canada. For a Timber Supply Area (TSA) in British Columbia the investigators have obtained unique access to extremely detailed site-level data, which are used by timber-supply managers in the British Columbia Ministry of Forests when making harvesting decisions. In particular, they have access to elaborate linked biological and geographical data in the form of a Geographical Information System (GIS) at the grid level which, in this case, is a hectare or 100 meters square. Thus, for every hectare in the Fraser TSA, which is located near Vancouver, British Columbia and contains several hundreds of thousands hectares, officials at the Ministry of Forests provide the investigators with a wide variety of biological, engineering, and geographical information relevant to harvesting timber. In addition, they also have access to the harvesting strategies proposed and, in some cases, the decisions implemented by the Minister of Forests, so they can compare our estimated decisions with actual ones. In developing practical harvesting solutions for timber, they apply the method of stochastic dynamic programming. The goal of the project is to make the following contributions: First, this project takes geography seriously, both in the planar sense and in the three-dimensional sense. Second, it takes site-specific heterogeneity seriously both on the cost side in terms of felling and transportation and on the growth and yield side in terms of heterogeneous stands of timber. Third, it models initial conditions. In particular, it does not take as the starting point a steady-state allocation, or even an optimal allocation. Instead, it takes the existing uneven-aged timber stand as given and derives the optimal policy function, the optimal timber-harvesting profile, in terms of this age distribution. Fourth, this project uses best-practice biological methods to model the dynamics of uneven-aged forest growth and yield. Fifth, in the past economists and foresters have typically demonstrated their methods by making extremely simple assumptions concerning the stochastic nature of timber prices and volumes so that closed-form examples could be solved. This research implements recent developments in computational methods so that practitioners can solve numerically for the optimal policy function in realistic biological, economic, and spatial environments.

在环境和自然资源经济学中，可再生自然资源的管理对经济学家引起了极大的兴趣，因为永久管理资源的前景具有实际的重要性和现实世界中的意义。此外，由于过去管理某些可再生自然资源的失败会导致几种物种的灭绝，因此制定了管理持续可再生自然资源的实用策略既及时又有用。 该项目详细研究了加拿大不列颠哥伦比亚省的一种可再生自然资源木材的管理。 对于不列颠哥伦比亚省的木材供应区（TSA），调查人员已经获得了极为详细的现场数据的独特访问权限，在做出收获决策时，不列颠哥伦比亚省森林部的木材供应经理使用这些数据。特别是，他们可以在网格水平上以地理信息系统（GIS）的形式访问精心链接的生物学和地理数据，在这种情况下，这是一公顷或100米广场。因此，对于位于不列颠哥伦比亚省温哥华附近的Fraser TSA的每公顷土地，森林部的官员为调查人员提供了各种各样的生物学，工程和地理信息。此外，他们还可以使用提出的收获策略，在某些情况下是森林部长实施的决定，因此他们可以将我们的估计决定与实际决定进行比较。在开发木材实用收获解决方案时，它们采用了随机动态编程的方法。 该项目的目的是做出以下贡献：首先，该项目在平面意义和三维意义上都认真对待地理。其次，就砍伐和运输以及在异质木材的木材上而言，在成本方面，在成本方面都认真对待特定地点的异质性。第三，它建模初始条件。特别是，它不认为起点是稳态分配，甚至是最佳分配。取而代之的是，根据此年龄分布，它采用了现有的不均匀木材站，并得出了最佳的策略功能，即最佳的木材收获概况。第四，该项目使用最佳实践生物学方法来模拟不均匀的森林生长和产量的动力学。第五，在过去的经济学家和森林人中，通常通过对木材价格和量的随机性质做出非常简单的假设来证明他们的方法，以便可以解决封闭式的例子。 这项研究实施了计算方法的最新发展，因此从业者可以在现实的生物，经济和空间环境中以数值解决最佳策略功能。