Political-Economy Arguments for a Uniform Tariff
评估了政府偏好统一关税的三类政治经济学理由：搭便车效应减少游说、投入品价格效应抑制最终品生产商保护需求、预先承诺效应增加未来政府保护特定行业的成本。结论是这些论据均不构成统一关税的绝对理由，需具体分析。
Uniform tariffs have become increasingly popular in recent years, yet their economic rationale is not strong.We identify and evaluate three sets of reasons as to why governments may prefer tariff uniformity as a means of alleviating political motives for excessive protection.First, a free-rider effect may be conducive to less lobbying under a uniform tariff regime than under a regime in which tariffs are allowed to differ.Second, an input-price effect may dampen the enthusiasm of final-goods producers for import protection.Third, a precommitment effect may increase the cost to a future government of protecting favored sectors.None of these arguments provides an unambiguous, airtight case for tariff uniformity.The decision on uniformity has to be made on a case-by-case basis.