CAREER: New Dynamic Public Finance -- from Theory to Policy

经济学的核心问题之一是如何设计税收和社会保险政策。该项目涉及宏观经济学和公共经济学交叉领域的广泛项目，将有助于从理论上理解政策应该如何实施，并提供可供世界各地政策制定者使用的实际建议。最近出现的新动态公共财政（NDPF）方法为回答这些问题提供了新的方法和框架。然而，新政治方案的方法主要是提供理论或暗示性的数字预测，而不是可执行的政策建议。该项目的主要目标是将npf从理论转向政策。该项目的研究结果将直接关系到资本和劳动税、社会保障和残疾保险制度的设计。npf的主要重点是动态环境下的政策设计，因为许多税收（如资本税）和许多社会保险计划（如社会保障）是动态的或跨期的。ndf方法将两个基本问题带到了动态环境中最优政策设计的前沿：(1)社会希望再分配或社会保险，因为代理人在其一生中经历了重大的不利冲击，例如，成为残疾；(2)激励很重要，因为这些冲击是私人信息，例如，许多形式的残疾是众所周知的难以确定的。这种方法已经对重要的政策问题产生了新的影响，包括对资本收入征税以及残疾和社会保障制度的设计。具体而言，本项目实现了两个目标：1.；从现实的定量模型中得出可实施的政策含义。设计考虑政治经济因素的政策。更广泛的影响：议程的第一部分是使用量化模型研究最优政策，这些模型可以捕捉经济环境的经验相关特征。这些模型一旦开发出来，就可以作为税收和社会保险政策设计的主力模型。这里的主要重点是定量的，并提供资本和劳动税的决定因素和最优形式，以及最优社会保险计划（如社会保障）的福利形式。最后，本项目将从理论上和定量上关注新动态公共财政中一个很大程度上未被探索的部分——如何在商业周期中优化设计税收和社会保险。研究议程的第二部分与第一部分密切相关，因为除非考虑到政治家实施这些政策所面临的限制，否则最佳政策的设计将是无关紧要的。本项目分析了如何设计政策，不仅要考虑社会保险与激励之间的权衡，还要考虑自私自利的政客的激励。其次，本项目研究如何设计可持续的税收制度，即能够减轻政治激励问题。最后，它研究了在什么条件下，市场可以比中央集权政府实现更好的分配。

One of the central questions in economics is how to design taxation and social insurance policy. This project pursues a broad program at the intersection of macroeconomics and public economics that will both contribute to the theoretical understanding of how policy should be conducted and provide practical recommendations that can be used by policymakers around the world. A recently emerged approach, New Dynamic Public Finance (NDPF), provides new methodology and a framework to answer these questions. However, the NDPF approach has delivered mostly theoretical or suggestive numerical predictions rather than implementable policy recommendations. The primary goal of this project is to move NDPF from theory to policy. Results of the project would be directly relevant for the design of capital and labor taxes, Social Security, and disability insurance system.The main focus of NDPF is the design of policy in dynamic settings, as many taxes such as tax on capital and many social insurance programs such as Social Security are dynamic or intertemporal. The NDPF approach brings two fundamental issues to the forefront of the design of optimal policy in dynamic settings: (1) society desires redistribution or social insurance as agents experience significant adverse shocks during their lifetime, e.g., becoming disabled, and (2) incentives are important because these shocks are private information, e.g., many forms of disability are notoriously difficult to ascertain. This approach has already delivered novel implications for important policy issues that include taxation of capital income and design of disability and social security systems. Specifically, this project achieves two objectives:1. Derive implementable policy implications in realistic quantitative models.2. Design policy that accounts for political economy considerations.Broader Impacts: The first part of the agenda is to study optimal policy using quantitative models that can capture empirically relevant features of the economic environment. Once developed, these models can be used as workhorse models for policy design of taxation and social insurance. The main focus here is quantitative and delivers the determinants and optimal form of capital and labor taxes as well as the form of benefits of optimal social insurance programs such as Social Security. Finally, this project focuses theoretically and quantitatively on a largely unexplored part of the New Dynamic Public Finance - how to optimally design taxes and social insurance over the business cycle. The second part of the research agenda is intimately linked to the first part, as the design of optimal policies would be irrelevant unless it takes into account the constraints that are faced by politicians implementing such policies. This project analyzes how policies should be designed to account for not only the social insurance versus incentives tradeoff but also the incentives of self-interested politicians. Second, this project studies how to design tax systems that are sustainable, i.e., able to mitigate political incentive problems. Finally, it investigates under which conditions markets can achieve superior allocations than those achieved by centralized governments.