Business cycle downturns come in many forms. Some are big, others small. Some are long, others short. Some result from policy errors or euphoric booms, while others are the consequence of external events.

Nevertheless, downturns have some common features and regularities. Among those that have been reasonably stable over much of the past half century are the relationships among unemployment, activity and federal budget deficits. Using these, we explore the impact of the U.S. COVID-19 economic downturn that began last month.

To sum up, recent labor market developments already make clear that we are in the midst of the deepest recession since the 1930s. In fact, the coordinated shutdown of a large swath of the American economy has made this plunge more rapid than that of the Depression. Whether we are at the start of a second Depression depends greatly on how long we keep the economy in a state of suspended animation.

If the lockdown extends from weeks to months, the short-term pain will turn into long-term scarring. The longer it takes to reopen businesses safely, the more damage we will do to the many linkages and networks (including lender-borrower, supplier-user and employer-employee relationships) that make up the fabric of the economy. As the wave of bankruptcies grows, damage to the financial system will increase, as will the resulting harm to the economy’s productive capacity….