Prices or Quantities Can Dominate Banking and Borrowing*
研究可交易排污许可的跨期银行与借贷机制，发现固定价格或固定数量在预期福利上优于时间灵活机制，且原始价格与数量比较公式足以刻画银行与借贷的监管作用。
Abstract The possibility of intertemporal banking and borrowing of tradable permits is often viewed as tilting the various policy debates about optimal pollution control instruments towards favoring such time‐flexible quantities. This paper shows that this view can be misleading, at least for the simplest dynamic extension of the original “prices versus quantities” information structure. The model of this paper allows firms to know and act upon the realization of uncertain future costs two full periods ahead of the regulators. For any given circumstance, the paper shows that either a fixed price or a fixed quantity is superior in expected welfare to time‐flexible banking and borrowing. Furthermore, the standard original formula for the comparative advantage of prices over quantities contains sufficient information to completely characterize the regulatory role of intertemporal banking and borrowing. The logic and implications of these results are analyzed and discussed.