Everyone should be wearing a face mask now, whether they are sick or healthy. We can make our own masks to ensure we're not taking them away from health care workers. In several Asian countries that are successfully lowering the number of infections from Covid-19, mask wearing is widely promoted, so why isn’t the U.S. following suit?

In China, authorities use drones fitted with loudspeakers to scold people who don’t wear masks outdoors. In South Korea, the government rationed masks, staggering days when citizens could buy a limited number so there would be enough for everyone. Leaders in Hong Kong and Taiwan set a good example by wearing masks when making public appearances, often flanked by a cadre of mask-wearing staffers.

The consistent messaging from authorities in Asia is in stark contrast with American officials who have fed confusion and distrust. On February 29th, Dr. Jerome Adams, the U.S. Surgeon General, tweeted, “Seriously people- STOP BUYING MASKS! They are NOT effective in preventing general public from catching #Coronavirus, but if healthcare providers can’t get them to care for sick patients, it puts them and our communities at risk!”

Dr. Adams’ recommendation is dead wrong. It fails to understand consumer psychology and, in the course of time, will prove to have cost thousands of lives. While the standard advice to stay home and wash your hands still stands, many people work in essential services outside the home and almost everyone needs to go outside once in a while for groceries and other supplies. Dr. Adams makes three arguments which lead to one terribly wrong conclusion.

As a behavioral designer, I believe we need to adjust our public health messaging for the way people behave in the real world.

Scarcity Encourages Hoarding

First, it’s true that people should stop buying masks. But telling people to do so only encourages hoarding. The scarcity heuristic, well known to social psychologists and anyone with common sense, tells us that people are more likely to value something when it suddenly becomes scarce. Telling people that there’s a run on face masks only makes them more likely to stock up before supplies run out.

Rather than telling people to stop and hoping they’ll listen, authorities should follow the steps implemented in South Korea and ration certain masks while there is a critical shortage. Heavy duty N95 masks and other medical-grade respirators should be reserved by law for health care facilities with an amnesty for people who hoarded them to provide an incentive to sell them to hospitals who are eager to buy.

Social Proof Changes Human Behavior

Second, it’s true that face masks alone do not prevent all infections. However, wearing masks has been shown to be more effective at preventing transmission of disease than hand-washing alone and significantly more effective when combined with other interventions.

Furthermore, healthy people wearing face masks protect the greater population. People need social proof to change their behavior. Asking only sick people to wear a face mask makes little sense, since people are unlikely to want to advertise they are ill. Covid-19 can infect people who never show symptoms, don’t know they’re sick, and yet may infect others. If we all started wearing face masks in public, we’d limit the spread of the disease by making mask-wearing socially acceptable, as it is today in much of Asia.

Some argue that people don’t know how to wear a mask properly and may end up touching their faces more. However, no studies have shown increased transmission rates when the general public is encouraged to wear masks and people can learn the simple steps for handling masks properly.

Contradiction Hurts Credibility

Dr. Adams’ third mistake is his failure to explain why a health care provider without a mask is at risk while the rest of us can walk around mask-free and risk-free. The virus doesn’t ask to see your medical credentials after all, and the contradiction hurts his credibility.

Adams should clarify his message and issue a call to action. Masks do appear to reduce transmission, and there are other options than buying them. Americans should start making their own masks as quickly as possible.

Most people have the basic materials to make a mask right at home right now, and studies find homemade masks are more effective than no protection. Making our own masks will help save existing stock for healthcare professionals as manufacturers ramp up production in the coming months. It can increase the supply so that no mail carrier, food courier, or janitor needs to be without a mask.

It’s time to call forth the “can do” American spirit and encourage people stuck at home to start sewing. Instead of ill-conceived mixed messages, we can use social proof to make wearing a mask the new norm. Instead of wearing a button or lapel pin as people have done to show their support during past crises, let’s think of wearing a face mask as an act of solidarity. Wearing a mask shows we’re all in this together.