Damage from air pollution appears not to justify large reductions in automobile travel in typical US urban areas; but it does justify significant expenditure on control of pollution. But local conditions vary widely, and some categories of pollution were not covered
Topic: 12.6 Other
American inland waterway transport is subject to a complicated system of control by government agencies, which require knowledge of costs. Inland waterway costs have fallen slightly, and a large share of the market has come into the hands of a small number of firms. The authors find increasing returns to scale for size of firm and output.