A Study of Resource and Environment Policy and Dynamic Gains from Trade

这项研究的目的是从理论上分析一个只有自然资源作为收入来源的经济体是否能够长期生存。如果发展中国家试图仅靠向工业国出售开采的自然资源为生，他们可能无法确保自己的可持续性。他们自然会想到任何自力更生的方法。它真的可行吗？在这三年的研究期内使用的分析模型具有以下特点。1.考虑了两类库存变量：可再生资源和其他实物资本。2.利用这两种库存生产的复合商品用于消费和投资。3.库存水平的变化幅度受到不确定性的影响。第一个特征是在资源完全耗尽之前从理论上表达将自然资源转化为其他物质资本的要求的手段，因为作为生态…似乎没有意义如果资源虽然是可再生的，但可以假设最终不会枯竭(如果枯竭的概率肯定为零，那么除了资源的实际开采程度外，可持续性并不构成经济问题)，这就是更多的经济问题。第二个特征是确保将生产的商品优化配置到消费和投资中用于实物资本积累的机制，以便在经济得到最佳管理的假设下审查可持续性。最后，在最后一个特征中考虑了两种类型的不确定性。一种是随着时间的推移，库存水平的连续变化，另一种是离散时间间隔的库存跳跃。前者用布朗运动建模，后者用泊松过程建模。布朗运动最好地表达了这样一种情况，即库存水平的变化将随着时间的推移而不断扩大，即使在一定程度上观察到当前的库存规模，紧随其后的下一个时间段也会显示出很小的变化。另一方面，我们考虑了一种复合泊松分布，用于处理变化之间不同长度的有意义的随机变化，而不是随着时间连续发生的无限小的变化。主要结果是：(1)我们证明了这种经济在确定性条件下存在稳态，即不存在模型的第一特征；(2)不确定条件下资源的最优开采水平小于确定性条件下的资源最优开采水平，但最优资源消耗水平经受住了不确定性的引入；(3)我们建立了关于这种经济的毁灭概率和生存概率的几个命题。较少

The purpose of this research is to theoretically analyze whether or not an economy being only endowed with a natural resource as the source of income can survive over the long time. Developing countries may not secure their sustainability if they try to live solely on selling excavated natural resources to industrial countries. They would naturally think of any method of self dependence. Is it really viable?The analytical model used in this three year research period has the following characteristics. 1. Two types of stock variables, a renewable resource and other physical capital, are considered. 2. A composite commodity produced by using these two stocks is utilized for consumption and investment. 3. The magnitude of changes in stock levels is subject to uncertainty. The first characteristic is the device for theoretically expressing the requirement of transforming natural resource to other physical capital before the resource completely depletes, since it seems meaningless as an eco … More nomic problem if the resource, though renewable, can be assumed ultimately non-exhaustible (if the probability of exhaustion is zero for sure, sustainability does not constitute an economic problem apart from actual levels of instantaneous excavation of the resource). The second characteristic is to secure the mechanism of optimally allocating the produced commodity into consumption and investment for physical capital accumulation in order to examine the sustainability under the assumption that the economy is optimally managed. Finally, two types of uncertainty are considered in the last characteristic. One addresses for continuous changes in the level of stock as time elapses and the other for jumps in stock with discrete time interval. The former case is modeled by using a Brownian motion and the latter by Poison process. Brownian motion is the best device to express the situation in which the variance of stock level changes will be continuously wider as time goes by even if the present size of stock is certainly observed and the immediately next time period will show a very little change. We consider, on the other hand, a compound Poison distribution for treating various lengths of intervals between changes with meaningful sizes occurring randomly rather than with infinitesimally small sizes happening continuously over time.The main results are that (1) we have proved the existence of steady state in this economy under certainty, namely without the first characteristic of the model, (2) the optimal excavation level of the resource under uncertainty is smaller than that under certainty but the optimal level of resource consumption survives the introduction of uncertainty, and (3) we have establish several propositions on the ruin and surviving probabilities of this economy. Less