This paper examines how accounting comparability affects the monitoring role and the risk allocation role of capital markets. We develop the statistical and informational properties of accounting reports under varying degrees of comparability. A perfectly comparable accounting information system enables investors to perfectly infer the difference between any two firms' future cash flows although investors remain uncertain about either firm's cash flow. Comparability alleviates entrepreneurs' moral hazard problem by strengthening the price response to the relative accounting performance, but can induce excessive price risk as well as residual systematic cash flow risk. Unlike the investors (users) who earn their surplus by bearing the residual systematic risk, the entrepreneurs (preparers) do not find perfect comparability desirable. Hence, a standard setter would mandate higher comparability than preferred by preparers, but not perfect comparability.

本文研究了会计可比性如何影响资本市场的监督作用和风险分配作用。我们在不同程度的可比性下开发会计报告的统计和信息属性。完全可比的会计信息系统使投资者能够完美推断差异任何两家公司未来现金流量之间的比率，尽管投资者仍然不确定任何一家公司的现金流量。可比性通过加强价格对相对会计业绩的反应来缓解企业家的道德风险问题，但会诱发过度的价格风险以及剩余的系统性现金流风险。与通过承担剩余系统性风险赚取盈余的投资者（用户）不同，企业家（准备者）并不认为完美的可比性是可取的。因此，标准制定者会要求比准备者所希望的更高的可比性，但不是完美的可比性。