Scarce or abundant?: the economics of natural resource availability

Most natural resources that are used in production are non-renewable. When they become depleted they are lost for future use. Does it follow that the limited availability of natural resources will at some time in the future constrain economic growth as many environmentalists believe? While classical economists have shared the belief in limits to growth, the distinctive feature of modern neoclassical economics is its optimism about the availability of natural resources. This survey suggests that resource optimism can be summarised in four propositions. First, a rise in the price of a resource leads to a substitution of this resource with another more abundant resource and to a substitution of products that are intensive in this resource. Second, a rise in the price of a resource leads to increased recycling of the resource and to the exploration and extraction of lower quality ores. Third, man-made capital can substitute for natural resources. Fourth, technical progress increases the efficiency of resource use and makes extraction of lower quality ores economical. In a critical analysis of these four propositions it is shown that while the conjecture that natural resources will never constrain future economic growth is logically conceivable, we do not and indeed cannot know whether it will be possible in practice to overcome any resource constraint.