Optimal Policy in Dynamic Informationally Constrained Economies

这个项目融合了公共经济学的技术，这些技术分析了在存在信息摩擦的情况下的最优配置，以及宏观经济学中常见的动态经济分析。推动该项目的问题涉及宏观经济学和公共经济学的交叉领域：1.鉴于信息摩擦，什么是有效的政策？2.如果市场是非效率的(调查人员表明，在存在隐性交易的情况下，这一点通常是正确的)，那么政府干预应该是什么，比如银行监管和专利。研究人员在一系列关于动态最优税收的论文中开发了一系列技术。在Golosov，Kocherlakota和Tsyvinski(2003)中，他们得到了动态Mirrlees经济最优的一般特征。在Golosov和Tsyvinski(2003)中，他们研究了在动态私人信息和私人储蓄存在的情况下，残疾保险制度的最优设计及其实施。在Golosov和Tsyvinski(2004)中，他们研究了存在内生私人市场的动态信息约束环境下的最优税收政策，结果表明，具有隐藏交易的竞争性市场是非效率的。该项目进一步发展了理论含义，描述了新的应用，并为信息约束的动态隐藏贸易经济中的最优政策提供了定量评估。他们考虑了两个政策利益问题，其中隐藏交易发挥了重要作用：银行的流动性监管，以及最优专利理论。虽然这些应用程序看似不同，但它们有一个相似的理论结构--如何在存在私人信息和隐藏交易的动态环境中设计最优政策。首先，它们确定了银行在金融市场(交易)存在的情况下提供低效流动性的一般情况，并表明流动性充足率要求实现了最佳水平。其次，他们开发了一种创新模式，在这种模式下，专利排除了隐藏的贸易和复制，并确定了最优的专利政策。该项目的第一部分研究了银行作为流动性和风险分担提供者的模式。该模型中有两种类型的信息摩擦：对流动性的不可观察的需求和金融市场的存在。调查人员表明，银行没有考虑它们提供的合约如何影响金融市场的价格，与最优合约相比，它们提供的流动性太少。然后，他们确定了一个简单的干预措施--流动性充足率要求--来实现最优配置。该项目的第二部分发展了私人创新动态模型中的最优专利长度理论。信息摩擦是商品价值的私密信息，是对商品进行隐性复制和生产的可能性。调查人员坚持认为，专利法通过防止复制或生产一种产品，允许创新者进行价格歧视。研究人员表明，最优专利长度取决于价格歧视和提供创新激励之间的权衡。研究人员确定了两种技术的最优专利长度：体现良好的创新和基于外部性的创新。这一结果与传统上假设线性价格的创新文献有很大不同。然后，调查人员对这两个项目进行量化评估。他们开发了一个在金融市场存在的情况下由银行提供流动性的校准一般均衡模型，该模型允许在商业周期内对金融中介机构的最优监管进行数字评估。然后，他们研究创新的量化模型，以确定最优的专利政策。更广泛的影响：该提案将有助于政策制定者改进金融中介机构的法规设计，并改善专利政策。

This project merges techniques from public economics that analyze optimal allocations in the presence of informational frictions with the analysis of dynamic economies common in macroeconomics. The questions that motivate this project are on the intersection of macroeconomics and public economics:1. Given an informational friction what is an efficient policy?2. If markets are inefficient (which the investigators show is generally true in the presence of hidden trades) what should be government interventions such as bank regulations, and patents. The investigators have developed a range of techniques in a series of papers on dynamic optimal taxation. In Golosov, Kocherlakota, and Tsyvinski (2003) they derive a general characterization of the optimum for a dynamic Mirrlees economy. In Golosov and Tsyvinski (2003) they study optimal design of a disability insurance system and its implementation in the presence of dynamic private information and private savings. In Golosov and Tsyvinski (2004) they study optimal tax policy in a dynamic informationally constrained environment in the presence of endogenous private markets and they show that competitive markets with hidden trades are inefficient. This project further develops theoretical implications, describes novel applications, and provides quantitative evaluation for optimal policy in informationally constrained dynamic economies with hidden trades. They consider two questions of policy interest in which hidden trades play an important role: liquidity regulations of banks, and theory of optimal patents. While the applications are seemingly different, they share a similar theoretical structure -- how to design optimal policy in a dynamic environment in the presence of private information and hidden trades. First, they determine a general set of circumstances in which banks provide an inefficient level of liquidity in the presence of financial markets (trades), and show that a liquidity adequacy requirement implements the optimum. Second, they develop a model of innovation in which patents preclude hidden trade and copying and determine an optimal patent policy. The first part of the project studies a model of banks as providers of liquidity and risk sharing. There are two types of informational frictions in the model: unobservable demand for liquidity and the presence of financial markets. The investigators show that banks do not take into account how the contracts they offer affect prices on the financial markets and provide too little liquidity compared to the optimum. They then identify a simple intervention -- liquidity adequacy requirement -- that implements the optimal allocation. The second part of the project develops a theory of optimal patent length in a dynamic model of private innovation. The informational frictions are private information of the valuation of the good and possibility of hidden copying and production of a good. The investigators maintain that patents law, by preventing copying or production of a good, allows the innovator to price discriminate. The investigators show that optimal patent length depends on the tradeoff from the losses of price discrimination versus providing incentives to innovate. The investigators determine the optimal length of the patent for two technologies: good-embodied and externality based innovation. The results differ significantly from the literature on innovation that traditionally assumed linear prices. The investigators then provide a quantitative evaluation of both projects. They develop a calibrated general equilibrium model of liquidity provision by banks in the presence of financial markets that allows to numerically evaluate optimal regulation of financial intermediaries over the business cycle. They then study a quantitative model of innovation to determine optimal patents policy. Broader impact: The proposal will help policymakers to improve design of regulations of financial intermediaries and improve patent policy.