Optimal Fiscal Policy in a Business Cycle Model without Commitment

该提案的广泛影响是为美国和其他国家的公共政策提供信息。如何制定适应经济周期的财政政策，可以说是宏观经济学中最重要的问题之一。在大多数讨论中缺乏对所涉及的时间不一致问题的清晰理解。这种情况很不幸。例如，关于货币政策如何在没有承诺的环境中实施的研究对联邦储备系统或欧洲中央银行等新机构的设计产生了巨大影响，它被认为是过去二十年来货币政策质量明显提高的一个重要因素。如果类似的问题能被纳入财政政策的讨论，福利就能得到重要的改善。为了实现这一目标，该提案结合了标准的宏观经济工具、博弈论和计算科学的最新进展。它提高了我们对社会如何对不断变化的政府政策作出反应的动态的理解，帮助政府预测其决策的后果，并以透明和清晰的方式将正式建模与经验数据相结合。此外，该项目通过其方法论贡献，改进了分析复杂互动的工具，并将其应用于所有人类行为科学，不仅包括经济学，还包括政治学、社会学和其他普遍存在缺乏承诺和重复互动问题的学科。最后，由于使用了数学和计算机科学工具，当前的研究加强了人类行为的政治和经济背景与其他数学和信息技术学术团体之间的联系。

The broad impact of the proposal is to inform public policy, both in the U.S. and in other countries. How to set the fiscal policy over the business cycle is arguably one of the most important questions in macroeconomics. Absent in most discussions is a clear understanding of the time inconsistency problems involved. This situation is unfortunate. For example work on how monetary policy is conducted in environments without commitment has had a tremendous impact on the Federal Reserve System or on the design of new institutions as the European Central Bank and it has been regarded as a significant factor behind the apparent higher quality of monetary policy over the last two decades. If similar questions could be incorporated in the discussion of fiscal policy important welfare improvements could be obtained.To achieve this goal, the proposal mixes standard macroeconomic tools, game theory and recent advances in computational science. It improves our understanding of the dynamics of how society reacts to changing government policies, helps the government to anticipate the consequences of its decisions and integrates formal modeling with empirical data in a transparent and clear way. Also the project, through its methodological contributions, improves the tools to analyze complex interactions, with application along all the human behavior sciences, including not only economics but also political science, sociology and others where the problems of lack of commitment and repeated interaction are pervasive. Finally, because of its use of mathematics and computer science tools, the current research strengthens the links between the political and economic context of human behavior with other academic communities in mathematics and information technologies.