Financial markets are in meltdown mode as the coronavirus courses rapidly and all too undetectably throughout the world. But there is a simple thing the U.S. government can do right now, which would both slow the viral spread and limit the economic harm.

Give people and companies money.

Perhaps that intervention strikes you as a non sequitur. Dollar bills aren’t medicine, COVID-19 doesn’t discriminate by income, and—to be emphatically clear—the most important interventions to contain the virus itself are in the realm of public health, including expanding the availability of free and accurate testing kits, increasing our capacity to treat the ill, and isolating infected individuals.

Annie Lowrey: The stock market is tanking. Do nothing.

But the U.S. also needs financial help, immediately. Perhaps that is why President Donald Trump is reportedly considering measures to bolster the economy, even as he claims that the disease is no more threatening than the seasonal flu.

To see why the U.S. needs a stimulus package, look at Austin. The city’s wise decision to cancel the SXSW festival is devastating, wiping out nearly $1 billion in economic activity. The city’s “conference economy” is large and diverse, including security staff, tech crews, caterers, ride-hailing drivers, and hotel and restaurant staff. Thousands of people will lose an economic windfall they plan for all year. If they fall behind on rent or can’t pay utility bills next month, they’ll pull back spending on grocery stores and clothing outlets. The SXSW cancellation will reverberate throughout the region.