Estimating Long-Run Elasticities of Supply
Economists have devoted considerable effort to estimating long-run supply elasticities for competitive industries. Because economic growth leads to increased demands for most products (especially natural resources and other primary products), the reason for this interest is obvious. If long-run supply elasticities are high, real resource price will not increase rapidly over time. This same to be the case for relatively abundant or coal. Over time, real prices for these goods have not risen very rapidly in response to increasing demand. Indeed, in some cases, real prices may even have fallen because of technical improvements in production.
On the other hand, cases in which long-run supply curves are inelastic can show sharply escalating real prices in response to increased demand. Again, the ultimate causes for such an outcome relate to conditions in the market for inputs. In cases such as rare minerals (platinum, for example, which is used in automobile exhaust systems), increases demand may require the exploitation of very costly deposits. Perhaps an even more important source of increasing input costs is the market for skilled labor. When expansion of a market, such as that for medical care or computer software, creates new demand for a specialized labor input, wages for these workers may rise sharply, and that gives the long-run-sup-ply curve its upward slope.
Table 10-3 summarizes a few studies of long-run supply elasticities. Although there are considerable uncertainties about the some of these figures (and, in some cases, the markets may not obey all the assumptions of the perfectly competitive model), they still provide a good indication of the way in which conditions input markets affect long-run supply elasticities. Notice, in particular, that the estimated elasticities for some natural resources are quite high—for these, the constant cost model may be approximately correct. For goods that encounter rising labor costs (medical care) or that require the use of increasingly high-cost locations (oil and farm crops), supply can be rather inelastic.