The Public Capital Stock: Needs, Trends, and Performance
探讨美国公共基础设施资本存量的现状、历史趋势及绩效问题，分析联邦补贴对州和地方资本支出的影响，并讨论基础设施资本不足是否可能降低私营部门生产率增长。
The condition of America's roads, bridges, mass transit systems, and water and sewer facilities has become an issue of increasing controversy. One view holds that deterioration of this infrastructure has reached alarming proportions, and that a significant fraction of future national savings will be needed to reverse the damage of past neglect. Another view argues that there has been no sudden acceleration of decay in capital stock performance, that better facility management can often substitute for capital investment, and that attempts to greatly increase the size and condition of the public capital stock would place unsustainable pressure on financial markets, state and local government budgets, and the federal system of grants-in-aid. How extensive is the capital infrastructure problem? How did it arise, given the many federal government subsidies available for state-local capital expenditure? How much of the national capacity for capital formation should be allocated to solving the problem? If there is a divergence between actual and desired infrastructure capital, can the gap be closed without disrupting the growth of other sectors and governmental objectives? These questions are, unfortunately, much easier to pose than to answer. There is only limited information about the size and condition of the stock of public infrastructure capital, and much of the available information has been assembled from the perspective of engineering or planning standards. Needs assessments typically indicate the fraction of the infrastructure stock that falls below a specified (and somewhat arbitrary) level of performance, or indicate how much spending would be required to bring the existing stock up to the specified standard. While sometimes appropriate as a management tool, infrastructure needs estimates are formulated in isolation from other public and private capital needs and are thus ill-suited to the policy debate over national priorities. Despite significant data problems, some general conclusions about the infrastructure dilemma are possible. As a backdrop for these conclusions, the first section of this paper presents an overview of the historical trends in public sector capital formation and infrastructure condition. The following section discusses the factors shaping these trends, with particular attention to the supply and demand components of the capital spending decision. We then consider the question of whether existing trends will insure an adequate supply of public capital, and address the issue of whether a reduced quantity and quality of infrastructure capital may be expected to reduce private sector productivity growth.