That, in turn, could avoid the need for feared blockades that would wipe out 5% of US GDP, according to the report. "We found that face masks are associated with significantly better coronavirus outcomes," Jan Hatzius, chief economist at Goldman Sachs wrote in the report.
In April, the federal government issued a "recommendation" to wear masks in public. However, unlike countries like Germany, India, Italy, the United Kingdom, and Mexico, there is no national requirement to do so in the United States..
For example, Goldman Sachs said that only 40% of people in Arizona say they always wear a mask in public, compared to almost 80% in Massachusetts.
A national mandate would increase use "significantly", especially in states like Florida and Texas, where masks are used primarily on a voluntary basis, according to the Goldman Sachs report. Overall, a mandate could raise the percentage of people who wear masks by 15 percentage points nationwide.
"Our analysis suggests that the economic benefit of a face mask mandate and increased use of face mask could be considerable," wrote Hatzius.
Trump suggests masks are counterproductive
The findings contrast with Trump's skepticism towards the masks.
By contrast, Joe Biden, the alleged Democratic presidential candidate, has expressed support for a federal mandate for the masks.
"Wearing the mask is the best opportunity to keep this economy open, keep us working, stay safe, and help us as we move toward that vaccine where we are in a much stronger position than any other country," McCarthy said.
V-shaped recovery is a "fantasy"
The debate comes as health experts and investors grow increasingly nervous about the recent surge in coronavirus infections in the Sun Belt states, especially Arizona, Texas, and Florida.
"In a March repeat, the virus appears to be starting to spiral out of control in about a third of the United States," Ethan Harris, a global economist at Bank of America, wrote in a note to customers on Tuesday.
Morgan Stanley biotechnology analyst Matthew Harrison warned in a report to clients Tuesday that if Texas and Florida "don't break their exponential growth in the next 10 days, we would expect the outbreak to become uncontrollable without more aggressive measures."
All of this casts further doubt on the already limited prospects for a V-shaped recovery in the US economy from the pandemic.
"With half the country opening slowly and the other half closing slowly, the economy could stabilize overall," wrote Harris of Bank of America.
Constance Hunter, chief economist at KPMG, told CNN Business that she fears the pandemic will leave "lasting scars" on the job market and that entire companies "will not return."
"There's no way we have a V-shaped recovery. It's a fantasy," Hunter said.
The second wave looms
The good news is that medical experts remain optimistic about the prospects for a vaccine.
However, more than three-quarters say a vaccine won't be widely available until the end of next year or more. And more than half (52%) say there will be a second wave severe enough to cause government-imposed closings and restrictions.
Any closure would harm the economy. Goldman Sachs estimates that the combination of government restrictions and social distancing eliminated 17% of the United States' GDP between January and April.
"A national face mask mandate could replace renewed locks that would otherwise subtract nearly 5% of GDP," Goldman Sachs argued in Monday's report.
However, politics marks the path of such a mandate. "So will the United States adopt a national facial mask mandate? This is uncertain, in part because masks have become a political and cultural problem," Hatzius wrote.
Hunter, the KPMG economist, said she is "shocked, stunned and sad" because the masks have become such a contentious political issue that they could allow life to return to normal earlier by depriving the virus of the hosts.
"The virus has taken away our freedom and people say, 'I want to get my freedom back,'" Hunter said. "But the mask is a wrong target for one's negative feelings. The mask can actually give us our freedom."