The Role of Public Employment in Stabilizing the Macroeconomy: Theory and Evidence

在世纪后半叶，西方世界的许多国家都建立了广泛的政府支出计划。在商业周期研究中，一个被低估的事实是，在许多发达经济体中，政府现在雇用了很大一部分劳动力：英国和美国为16%，欧盟为20%（经合组织，2019）。因此，政府在经济衰退期间的行为对于直接决定失业率的变化至关重要：政府是否也解雇工人，从而加剧失业率的上升，或者他们是否雇用工人，并可能填补一些空缺？尽管政府雇用对劳动力市场有这种“直接”影响，但大多数关于政府周期性作用的研究都是从政府雇用中抽象出来的。相反，大量文献探讨了“政府支出乘数”到底有多大这个古老的问题。从经验上讲，这衡量的是政府支出的典型抽象增长对经济的影响。从理论上讲，如果政府通过从私营部门购买更多的商品来增加支出，那么经济会如何反应，因此对劳动力市场的任何影响都是“间接的”。在本文中，我的目标是填补这一文献空白，通过实证和理论研究：1）政府就业的变化如何“直接”影响商业周期中的失业率，第二，政府在经济衰退期间暂时增加就业以对抗失业是否是一个好主意，以及这种政策与传统财政刺激或转移支付（如失业救济金）等更深入探索的工具相比如何。为了回答这些问题，我打算写一个三章的论文，这将建立在宏观经济学几个领域的最新进展的基础上。我的第一章将研究公共就业在商业周期中的作用。这样做需要一个现实的劳动力市场，为此，我使用了Coles和Kelishomi（2018）在搜索和匹配文献方面的最新进展。他们认为，私营部门公司在为失业工人创造新工作方面往往行动迟缓，这与标准搜索和自由进入的匹配模型不同，并估计就业创造在数据中非常缺乏弹性。我在本章中的主要观点是，如果私营部门的就业创造在这种情况下是缺乏弹性的，那么在经济衰退期间，公共就业的变化对失业率有着强大的影响。我将建立一个定量模型来估计公共就业对经济的影响，包括公共就业“乘数”，并估计政府就业的变化对英国失业的历史贡献。11111111111111在第二章中，我将扩展模型，以研究异质性以及公共就业如何影响风险和不平等。我将首先扩展一个两主体新凯恩斯主义（TANK）模型（Cantore and Freund 2020; Ravn and Sterk，2020），以包括第1章中的公共就业和劳动力市场模型。这在很大程度上建立在我的MRes论文的工作上。然后，我将把这个模型扩展成一个成熟的异质主体新凯恩斯主义（HANK）模型（Auclert et al. 2018; 2020; Kaplan et al. 2014; 2018;哈格多恩et al. 2019）。据我所知，这将是第一个使用TANK或HANK模型研究公共就业的模型，因此我将能够使用最具创新性的商业周期模型来研究政府就业、不平等和总需求之间的相互作用。在第三章中，我将以COVID大流行为背景，研究流行病对就业的影响以及公共就业如何减轻封锁的影响。为此，我将联合收割机与第一章中的模型结合起来，研究公共就业在流行病期间支持健康和失业的联合作用。

During the second half of the 20th century extensive government spending programs have been established by many countries in the Western world. It is an underappreciated fact in business cycle research that governments now employ large fractions of the workforce in many developed economies: 16% in the UK and the US, and 20% in the EU (OECD, 2019). The behaviour of the government during a recession is therefore crucial in directly determining what happens to unemployment: Is the government also firing workers, and therefore adding to the rise in unemployment, or are they hiring workers, and potentially picking up some of the slack?Despite this "direct" effect of government employment on the labour market, most research on the cyclical role of the government abstracts from government employment. Instead, a voluminous literature tackles the age-old question of how large the "government spending multiplier" is. Empirically, this measures the effect on the economy of a typically abstract increase in government spending. Theoretically, this asks how the economy responds if the government increases spending by purchasing more goods from the private sector, and therefore any effects on the labour market are instead "indirect".In this dissertation, I aim to fill this gap in the literature, by investigating both empirically and theoretically 1) how changes in government employment "directly" contribute to unemployment over the business cycle, and 2) whether it is a good idea for the government to temporarily increase employment during recessions to fight unemployment, and how this policy compares to the more-explored tools of traditional fiscal stimulus, or transfer payments such as unemployment benefits.In order to answer these questions I propose to write a three-chapter dissertation, which will build on recent advances in several fields of macroeconomics.My first chapter will study the role of public employment over the business cycle. Doing so requires a realistic labour market, and for this I use recent advances in the search and matching literature by Coles and Kelishomi (2018). They argue that private sector firms tend to be sluggish at creating new jobs for unemployed workers, unlike standard search and matching models with free entry, and estimate that job creation is very inelastic in the data. My key insight in this chapter is that if private sector job creation is inelastic in this way, changing public employment during recessions has powerful effects on unemployment. I will build a quantitative model to estimate the effect of public employment on the economy, including a public employment "multiplier", and estimate the historical contribution of changes in government employment to unemployment in the UK. 11111111111111111In my second chapter, I will extend the model in order to study heterogeneity and how public employment affects risk and inequality. I will first extend a Two-Agent New Keynesian (TANK) model (Cantore and Freund 2020; Ravn and Sterk, 2020) to include public employment and the labour market model from chapter 1. This builds heavily on the work from my MRes thesis. I will then extend this model into a full-blown Heterogeneous-Agent New Keynesian (HANK) model (Auclert et al. 2018; 2020; Kaplan et al. 2014; 2018; Hagedorn et al. 2019). To the best of my knowledge, this will be first model studying public employment using either TANK or HANK models, so I will be able to study the interaction between government employment, inequality, and aggregate demand using the most innovative business cycle models.In my third chapter, motivated by the COVID pandemic, I will study the effect of pandemics on employment and how public employment can mitigate a lockdown's effects. To do so I will combine an epidemiological SIR model with the model in chapter 1 to examine the joint role of the public employment in supporting health and unemployment during the pandemic.