Hysteresis and Business Cycles
综述了近期关于经济冲击对GDP产生持久影响的实证与理论文献，指出衰退时需更积极的货币与财政政策以避免永久性创伤，而繁荣期的高压经济可能带来长期正面效应。
Traditionally, economic growth and business cycles have been treated independently. However, the dependence of GDP levels on its history of shocks, what economists refer to as “hysteresis,” argues for unifying the analysis of growth and cycles. In this paper, we review the recent empirical and theoretical literature that motivates this paradigm shift. The renewed interest in hysteresis (or “scarring” in recent parlance) has been sparked by the persistent impact of the global financial crisis —as GDP in advanced economies remained far below the precrisis trends for over a decade—and recent concerns about the lasting impact of the COVID-19 shock. The findings of the recent literature have far-reaching conceptual and policy implications. In recessions, monetary and fiscal policies need to be more active to avoid the permanent scars of a downturn. And in good times, running a high-pressure economy could have permanent positive effects.