Analyzing the economic impact of the COVID‐19 pandemic of 2020 requires an appreciation that price signals were no longer primary determinants of supply and demand. Economic agents were acting out of health fears, government‐mandated shutdown rules, and dealing with financial distress. The economy had entered a state that was far from equilibrium. Orthodox tools, such as comparative equilibrium analysis, can tell one about state “A” and state “B,” but provide no guidance as to how to analyze the phase transition. We turn to the physics of phase transitions to help us understand what essentially was a network collapse. The analysis is extended to examine whether the initial policy responses were more likely to cushion the blow or to accelerate the eventual economic recovery, which is extended into an examination of Modern Monetary Theory. Finally, we study the behavioral changes induced by the pandemic that are likely to be long‐lasting and impact the pace of the recovery. And we note a variety of data anomalies that are sure to vex empirical researchers as they study the pandemic of 2020.

中文翻译：

---

从相变到现代货币理论：分析2020年大流行的框架

分析2020年COVID-19大流行的经济影响，需要认识到价格信号不再是供求的主要决定因素。经济代理人出于对健康的担忧，政府强​​制性的停工规则以及应对财务困境而采取行动。经济已进入远非均衡的状态。比较平衡分析之类的正统工具可以告诉您有关状态“ A”和状态“ B”的信息，但没有提供有关如何分析相变的指导。我们转向相变的物理学，以帮助我们了解网络崩溃的本质。分析的范围扩大到检查最初的政策反应是更可能缓解打击还是加速最终的经济复苏，并扩展到对现代货币理论的考察。最后，我们研究了由大流行引起的行为改变，这些改变可能是长期的，并且会影响恢复的速度。而且，我们注意到各种数据异常现象肯定会困扰经验研究人员，他们正在研究2020年的大流行。