An Operational Measure of Liquidity
将资产出售过程嵌入搜索环境，给出了流动性的精确定义：流动性是资产在最优出售策略下的预期出售时间，该定义与凯恩斯等主流流动性概念兼容。
Embedding the process of selling an asset in a search environment enables one to provide an exact definition of liquidity: an asset's liquidity is the expected time until it is sold while pursuing an optimal (in the sense of maximization of expected discounted net proceeds) policy. This analysis reveals that this definition is compatible with most other notions of liquidity and, in particular, with those of John Maynard Keynes, impatience, the discount associatedwith a quick sale, predictability, and flexibility. Copyright 1986 by American Economic Association.