Although some studies have concluded that masks help stop the spread of COVID-19, usually they have failed to replicate real-world situations.  A common approach is to evaluate the effectiveness of mask material at stopping the expulsion or intake of the aerosols presumed to be the airborne carriers of the virus.  Useful information, perhaps, but at this stage, what we need to know is whether the widespread use of masks is measurably reducing the risk of death from the disease.  To continue requiring the use of masks makes sense only if there is compelling data that death rates are lower for people who wear masks than it is for people who do not.

We have no way of measuring whether or how much and how appropriately individuals wear masks, but state mandates that people wear them are predicated on the notion that more people will do so if they are threatened with a fine or punishment.  Thus, it makes sense to demand that states with mask mandates have lower COVID-19 death rates than states that don't.  If states with mask mandates are not experiencing lower rates than states without them, the citizenry should insist that the burdensome policy of requiring masks be abandoned.

Logic or speculation alone cannot provide a reliable answer to the question of mask effectiveness.  Neither can the judgments and proclamations of politicians or even public health experts.  What we need is data.

The Data

At this URL, it is possible to extract Census Bureau estimates of population for individual states as of July 1, 2020.

The Centers for Disease Control maintains a website that reports the total number of people who have died from COVID-19.  Updated daily, the table provides the figures for each state and for the country as a whole.  The state figures for virus deaths were extracted from this source on or about February 16.

U.S. News and World Report published an article identifying which states have and have not mandated masks.  For those states with a mask mandate, the article tells when the mandate was put into effect.

Those three sources provided the raw data for everything that follows.  At the end of this article, I will link to a table containing all the data that were extracted from those sources to answer the question of mask effectiveness.

The Study

The question is, "Do states with mask mandates have lower COVID-19 death rates than states with no mandate?"  If they do, the enforced wearing of masks may have been a reasonable approach to limiting deaths from COVID-19.  Otherwise, the rationale for imposing mask mandates disintegrates. In a similar fashion, states that never imposed a mask mandate can readily justify their behavior only if their COVID-19 death rates do not exceed those of the mask-mandated states.

Only ten states have had no mask mandate of any sort; the other forty imposed mask mandates that required one to be worn at all indoor venues and in all outdoor situations that challenge the six-foot distancing expectation.  The following map identifies the states in each group.

Using the data sources above, figures for the total population and the total number of COVID-19 deaths were extracted for each of the fifty states.  A COVID-19 death rate was calculated for each state by dividing its number of COVID-19 deaths by its population and then multiplying the result by 10,000.  The result was a COVID-19 death rate indicating the number of deaths per 10,000 people.  By sorting these individual state rates into two groups — masks mandatory versus masks voluntary — I could calculate the average COVID-19 death rate for each group.

States with a mask mandate: 13.0 deaths per 10,000 population.

States with no mask mandate: 12.6 deaths per 10,000 population.

Since the average COVID-19 death rate is actually lower for the voluntary mask states than it is for the mandated mask states, it is incumbent on advocates for the mask mandate to either reveal the data upon which they arrived at their conclusion or else stop making the claim that masks help keep people safe.

A variant on the theme of mask-mandated safety is the notion that states that adopted a mask mandate early on have lower death rates than the states that did so late.  Since the basis of this contention is that a greater length of time under the rule of mask has been an effective way of assuring low death rates, let us compare the performance of the ten earliest mask mandate states to the performance of the ten states that have never required a mask.

The US News & World Report article provided the information on the start dates for mask mandates. The following tables provide the comparison of the two groups.

Once again, the notion that masking up keeps us safe receives no support from the data.  In fact, the "bottom ten" outperform the "top ten" by a small but noteworthy margin (12.6 deaths per 10,000 versus 13.3 deaths per 10,000).  This hints at the possibility that masks actually elevate the death rate.  Would anybody care to investigate?

The impotence of mask mandates is particularly sobering since they usually proceed in lockstep with the other mandated actions intended to control the virus: hand-washing, social distancing, and lockdowns.  Since all four control tactics are chasing the same goal (stop the spread of the virus), these data revealing the ineffectiveness of masks may suggest that the other three control tactics are less effective than hoped.

This URL links to a summary of the data extracted at the previously identified URLs.

Image via Pxfuel.