Journal of Public Economics · 2025 · Edward E. Schlee
中文摘要
Weitzman（1974）提出，当成本和收益存在不确定性时，我们应当通过固定数量还是固定价格来规制一种物品。其福利标准——预期总剩余——隐含地对消费者偏好施加了两个很强的拟线性假设：对收入风险持中性态度；收入效应不影响对该物品的价值评估。这两点对于评价不确定性下的配置均具有一阶重要性。本文考察当受规制物品为公共品时，风险厌恶如何影响价格规制与数量规制之间的选择。本文给出了固定价格下的福利——以确定性等价之和表示——更高的条件；这些条件允许风险厌恶程度任意高，尽管在固定数量下，消费者并不承担数量或收入的不确定性。该结论关键取决于收益不确定性；这种不确定性虽存在于 Weitzman 的分析中，却与其结论无关。由此产生的一个意外结果是，风险厌恶构成了反对数量规制的一项令人意外的新论据。
Abstract
Weitzman (1974) asks whether we should regulate a good by fixing quantity or by fixing price when cost and benefit are uncertain. His welfare criterion—expected aggregate surplus—tacitly imposes two strong quasilinearity assumptions on a consumer’s preferences: neutrality with respect to income risk; and absence of income effects on the valuation of the good. Both are matters of first-order importance for the evaluation of allocations under uncertainty. Here I ask how risk aversion affects the choice between the two when the regulated good is a public good. I give conditions for welfare—in the form of the sum of certainty equivalents—to be higher for a fixed price; the conditions allow arbitrarily-high levels of risk aversion, even though consumers bear no uncertainty about quantity or income with a fixed quantity. The conclusion depends crucially on benefit uncertainty, present but irrelevant in Weitzman. An unintended consequence is a surprising new argument against quantity regulation: risk aversion.