Tax Incentives and Equipment Investment
回顾了美国过去四十年对资本收入特别是生产设备收入的税收待遇的频繁变动，分析了这些变动对投资的影响，并指出稳定政策更有利于投资者。
OVER THE PAST FORTY YEARS, tax treatment of income from capital in general, and income from producer's durable equipment in particular, has been changed in the United States an amazing number of times. Depreciation allowances have been accelerated and then retarded; de-preciation methods have ranged from straight line to double-declining-balance; investment tax credits have been enacted, suspended, rein-stated, eliminated, re-enacted, and most recently, repealed again. In addition, both corporate and personal tax rates have moved over a substantial range. All of this tinkering with the tax structure is hard to justify on any eco-nomic basis; the long-run attitude of investors would be better served by a stable policy that insures that political risk will not be added to the al-ready considerable uncertainty about future after-tax returns. Why the frequent changes in business taxation have occurred is not clear. In gen-eral, the trend in tax rates has been downward, and reaching political consensus on this trend has been an uneven and contentious process. Inflation has at times created serious distortions in effective tax rates, and changes in the tax code may have been aimed at mitigating these ef-fects. Most importantly, various administrations have attempted to use tax stimulus for investment as part of their efforts to fine-tune economic activity through short-term fiscal policy changes. I gratefully acknowledge productive comments and assistance with data from Jane