Second is the way that the coronavirus is stifling growth. Many recessions, including the Great Recession and the 2001 downturn, intensify when demand evaporates from the economy. Struggling businesses lay off workers. Cash-strapped consumers stop buying houses and cars. Spooked investors stop pumping money into the risky, growing ventures that vitalize the economy in the long term. To stanch the damage and turn the business cycle around, central banks lower interest rates and soak up safe assets, encouraging investors to take on more risk; congresses and parliaments cut taxes and disburse money to towns, states, and households, also spending on things like bridges, schools, and environmental projects.

But the coronavirus is not just sapping demand from the economy. It is also affecting supply. The epidemic has already led to shortages of drugs, industrial chemicals, medical equipment, and consumer goods like smartphones, as factories in mainland China shutter and those closures disrupt complicated trade networks. Human labor is in short supply too, with workers forced to stay home. The virus is “no longer mainly a supply-chain issue,” a team of Standard & Poor’s analysts wrote in an alarmed note. “Both supply and demand effects are in play, and both are being amplified by tightening financial conditions.”

Washington and other governments around the world have two main levers to help their economies from tipping into free fall: fiscal policy and monetary policy. The problem is that both of those levers work primarily on the demand side of the economy, and cannot readily fix the bottlenecks the virus is causing. The Federal Reserve has already announced one surprise rate cut. But how is a somewhat-lower interest rate going to help an American assembly business that cannot get parts out of China? “The benefits of lower interest rates at this stage are questionable with a substantial part of the economic shock due to supply-chain disruptions and official restrictions on economic activity,” argues Brian Coulton, the chief economist at Fitch Ratings. Moreover, the Fed and other central banks have already pushed interest rates to historic lows; they are running out of their strongest ammunition.

That leaves fiscal policy, meaning additional spending by Congress and other legislative bodies around the world. President Donald Trump and his advisers are pushing a temporary payroll-tax cut that would shunt more money into workers’ pockets. But that kind of measure would do nothing to help families missing paychecks, unable to keep the lights on and the house stocked with groceries because their workplaces are shut down. It would do nothing to stop businesses from going bankrupt due to manufacturing disruptions. It would do nothing to aid households struggling because a breadwinner falls sick, or needs to help a sick relative.