Masks are worn or not worn for what they do and for what they symbolize. Passionate arguments, and even physical fights, have erupted between those who want the economy to open faster and those who want the lockdown to last longer. The eruptions often start when one person (usually a lockdowner) is wearing a mask and the other (usually an opener) is not.
So wearing a mask has come to symbolize support for lockdowns and not wearing a mask has come to symbolize support for opening. In the future, the virus may evolve, our knowledge of it may grow, and we may seek new ways to adapt and fight it. But based on what we know now, the openers should not stigmatize those who wear masks. By stigmatizing, they undermine their own health and the health of others, thereby increasing the costs of opening and risking a backlash that could make lockdowns even longer and harsher.
Those who seek a flourishing economy should praise, not stigmatize, those who wear masks. A flourishing economy depends on more than governments easing mandatory lockdowns. It also depends on consumers returning to a marketplace where they feel safe and respected. One way to protect, and thereby respect, the at-risk and the risk-averse is to wear a mask. Lockdowns will ease more quickly, and consumers will return to re-opened marketplaces more quickly, if masks change from symbols of lockdowns to symbols of openness.
Mask Effectiveness
Several Asian countries, including Hong Kong, Singapore, Taiwan, and Japan, have had less COVID-19 than might be expected based on their demographics, density, and closeness to China. Other factors may matter, but the widespread use of masks in those countries surely helped. A Yale white paper found that when the timing and extent of a lockdown was controlled for, countries with pro-mask norms had deaths growing at 11 percent per day compared with 21 percent in countries with no pro-mask norms.
Masks are classified as either N95, surgical, or cloth. Research suggests that the efficacy of N95 masks is greater than surgical masks, and the efficacy of surgical masks is greater than cloth masks. Medical researchers contrast the "efficacy" of a device under ideal research conditions, with the "effectiveness" of the device under actual clinical conditions.
Despite superior efficacy, some studies suggest that the effectiveness of N95 masks is roughly equal to the effectiveness of surgical masks. This puzzling finding may in part be due to the greater difficulty in breathing with an N95 mask—those tasked with wearing a surgical mask may be more likely to comply than those tasked with wearing an N95 mask.
But although in the COVID-19 pandemic, N95 masks have been prized as the gold standard, surgical masks and even cloth masks, can do much good.
A recent study collected exhaled breath samples from those with non-COVID-19 viral respiratory infections, when wearing a surgical mask and when not wearing a surgical mask. They found virus particles in 30-40 percent of the samples from those not wearing a surgical mask. They found no virus particles in the samples from outside the masks of those wearing a surgical mask. A 2010 study found that even simple cloth masks block the penetration of between 10 percent and 30 percent of small viral particles.
A team of economists, MDs, and other scholars, all based at Yale, estimate that a mask that blocks 10 percent of viral particles, produces a benefit of between $3,000 - $6,000 per person who regularly wears such a mask. The estimated benefit would be larger if a mask blocks more than 10 percent of viral particles but would be smaller if it was based on a less dire epidemiological model than that of the Imperial College of London's Neil Ferguson.
We have often heard from public health experts that we should wear masks to protect others if we might be asymptomatic carriers of COVID-19. In that case the masks might reduce the odds that we would spread the virus to others. But we also were told that our wearing masks would not protect ourselves from becoming infected. This defies common sense. If the masks block some particles from exiting to infect others, they also block some particles from entering to infect us.
Masks do not need to block all, or even most, virus particles, in order to benefit both others and ourselves. The more particles we exhale or expel, the more likely we will infect others; the more particles we inhale, the more likely we will infect ourselves. Even a modest mask reduces the particles exhaled and inhaled, and thereby modestly improves the odds.
COVID-19, Masks, and "Viral Loads"
Strictly speaking, a person’s "viral load" is the number of virus particles per volume of a person’s blood or sputum. Other things equal, the higher a person’s viral load, the more likely the person is to become infected with COVID-19, the more likely they will develop a severe case, and the more likely they will infect others. “Other things equal” includes the strength of the person’s immune system, which itself is influenced by factors such as gender, age, diet, weight, sleep, frequency of exercise, and underlying conditions such as cancers that are being treated with immunosuppressant drugs.
The stronger your immune system, the higher the initial viral load you can inhale without becoming infected. The concept of “viral load” helps us to understand some otherwise puzzling features of the COVID-19 pandemic. For example, one puzzle about COVID-19 is why so many clinicians with strong immune systems have become infected. One possible answer is that patients with severe cases of COVID-19 often need to be intubated to connect them to a ventilator. These severely ill patients are likely to have a high viral load. When they are intubated by clinicians, they can shed many particles, putting even clinicians with strong immune systems at risk.
The coughs of an infected person with a high viral load will likely shed more virus particles, and thus infect more of those with whom they interact. So those with a high viral load are more likely to be "super-spreaders," infecting dozens of people in a short period of time. Other things equal, the uninfected are more likely to receive a high viral load if they are close to the infected, and if the air is stagnant. So distancing helps, and so does good air circulation—outdoors is best; air flow and filtration can help indoors.
Masks help too; even those that only block 10 percent of particles. If the infected and the uninfected wear masks, the odds are lower that the uninfected will inhale a viral load sufficient to infect them. And if they do become infected, the odds are lower that their infection will be deadly.
Balancing the Costs of Masks
But what of the costs of choosing to wear masks? They make our faces hot? We can turn up the air conditioner. They steam our glasses? We can apply an anti-fog surfactant coating or wear contacts. Our iPhone does not open to us when we wear a mask? We can read our messages on our iWatches, and thank Apple for already tweaking their operating system to quicken the process of entering our iPhone passcodes.
A higher cost of what I propose is that we sometimes find it useful to see people's faces. Seeing my face helps you know it is me and helps you judge the tone and credibility of what I say. The deaf cannot read my lips if I wear a mask. Looters are easier to catch and punish if we can see their faces. But we may overestimate these costs and underestimate our ability to mitigate them.
Innovative entrepreneurs Allysa Dittmar and Aaron Hsu are selling transparent surgical masks through their ClearMask startup. And surprising research shows that many of us can learn much from just focusing on a person's eyes. Steven Johnson in Mind Wide Open (2005, pp. 37-40) took the "Reading the Mind in the Eyes" test in which he was shown 36 different pairs of eyes and was asked to judge which of 93 different emotions the person behind the eyes was feeling. He was sure that he would flunk the test but was shocked to learn that he only got five wrong. Much tacit knowledge about a person can be gleaned from just seeing their eyes.
Wearing a mask has costs, but they are smaller than the benefits. They can be mitigated, and they will not last forever. Hopeful but plausible forecasts, at this writing, suggest that an effective vaccine will start to be available by October, and be more widely available by January.
The case for lockdowns is based on its blocking the often-deadly externality that we impose on others when we infect them with COVID-19. The case for openness is based on its strengthening the economy and, more fundamentally, on its allowing individuals to exercise their freedom to choose.
Initially, it was feared that the spread of severe cases would overwhelm the healthcare system, resulting in a great many deaths, and because so much was unknown, the worst-case deadliness of the externality was very large. Lockdowns were mainly intended to “flatten the curve” so that ICUs would not be overwhelmed. Many Americans thought that, with so much unknown, a temporary lockdown was prudent. In places such as Omaha, where I live, much of the “lockdown” was voluntary. Most businesses could still operate, with some restrictions, but most did little business because customers were voluntarily choosing to stay home.
For the economy to improve in the short run, we need practices (less public transportation, less open office designs, masks) and drugs (remdesivir and other promising candidates) that will improve our odds of dodging infection or help mitigate the severity of infection. For the economy to flourish in the long run, we need drugs that cure or vaccines that protect.
The government can help by reducing regulations that block innovative new practices or the development of new drugs and vaccines. (I discuss this in my earlier article “Free to Choose a Possible Cure.”) Individuals can help too, by being alert to what we can do. Masks are not our magic bullet against COVID-19, but they improve our odds. For our own health, for the health of others, for a faster opening, for freedom, each of us should voluntarily choose to wear a mask.
References
On slower spread in countries with norms supporting mask use:
On the clinical equivalence of N95 and surgical masks:
- "N95 Respirators Vs Medical Masks for Preventing Influenza among Health Care Personnel: A Randomized Clinical Trial." - JAMA 322, no. 9 (Sept. 3, 2019): 824-33.
On the high efficacy of surgical masks in blocking viral shedding by the infected:
- "Respiratory Virus Shedding in Exhaled Breath and Efficacy of Face Masks." - Nature Medicine 26, no. 5 (May 2020): 676-80.
On the effectiveness of simple cloth masks at blocking viral particles:
- "Testing the Efficacy of Homemade Masks: Would They Protect in an Influenza Pandemic?" - Disaster Medicine and Public Health Preparedness 7, no. 4 (Aug. 2013): 413-18.
- "Simple Respiratory Protection—Evaluation of the Filtration Performance of Cloth Masks and Common Fabric Materials against 20–1000 Nm Size Particles." - The Annals of Occupational Hygiene 54, no. 7 (Oct. 2010): 789-98.
- "Professional and Home-Made Face Masks Reduce Exposure to Respiratory Infections among the General Population." - PLoS One 3, no. 7 (July 2008): 1-6.
On the Yale estimates of the monetary benefits of wearing a mask:
On viral load increasing the odds of infection, and increasing the severity, if infected:
On healthy clinicians infected by the high viral load they are exposed to when intubating patients:
Arthur Diamond
Arthur Diamond earned graduate degrees in philosophy and in economics from the University of Chicago, where he also was awarded a Post-Doctoral Fellowship with economics Nobel Prize laureate Gary Becker. He has been on the faculty at The Ohio State University, and is now Professor of Economics at the University of Nebraska Omaha (UNO), where he has been a recipient of the UNO Award for Distinguished Research or Creative Activity and the UNO Department of Economics Outstanding Economics Graduate Teacher award.