America�s Republicans Are Killing Their Voters
Jul 22, 2021
Jeffrey Frankel

Despite mounting evidence that vaccination leads to lower COVID-19
mortality rates, many in the US remain skeptical, if not downright
hostile. An analysis of the data that isolates the causal effect of voting
patterns clearly shows the heightened danger Republicans face.

CAMBRIDGE � On May 14, 1962, the agriculture commissioner of Montana,
Lowell Purdy, launched what would become one of the century�s great
platitudes. �If we can put a man on the Moon,� he declared, seven years
before the United States achieved President John F. Kennedy�s goal, �we
surely are capable of seeing that our temporary surplus agricultural
products are placed in many hungry stomachs of the world.�

Since then, the formula has become a clich� � precisely because it often
makes a pretty good point. Today, for example, one might point out: �If we
can produce vaccines that drastically decrease the transmission and
severity of COVID-19, we surely are capable of ending the pandemic.� And
yet, we have so far been unable to do so, largely because people simply
refuse to be vaccinated.To be sure, in some cases � especially in lower-
income countries � the primary impediment to large-scale immunization is
limited vaccine availability. But in a country like the US, the main
problem is vaccine hesitancy, even hostility. Although the Food and Drug
Administration has granted emergency approval to three vaccines � a
process that demands rigorous testing � many are convinced they are still
�experimental,� and thus unsafe.As Anthony Fauci, the head of the National
Institute of Allergy and Infectious Diseases at the US National Institutes
of Health, put it, there are two Americas, and their perceptions regarding
vaccination are separated by a wall. For the America that mistrusts
vaccines, the expertise of remote authorities and the logic of the
scientific method are unconvincing.Perhaps more tangible, real-world
evidence can change their minds. It is certainly piling up: recent data
show a strong negative correlation between vaccination rates and rates of
infection, hospitalization, or death from COVID-19 across the US. In the
week that ended on June 22, counties where 30% or fewer residents had been
vaccinated suffered 5.6 new COVID cases per 100,000 people, whereas
counties where more than 60% of residents had been vaccinated experienced
just 2.1 new cases per 100,000.On updated data, a one percentage-point
increase in the share of adults (and teenagers) who were fully vaccinated
in a given county as of June 9 was associated with a significant decline
in the COVID-19 death rate � 0.06 per 100,000 inhabitants � over the
subsequent 30 days (to July 9). That represents 2% of the total monthly
coronavirus-related deaths. One could extrapolate from this that the
statistical effect of reaching 100% vaccination would be to bring COVID-
related deaths close to zero.
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But, of course, correlation does not prove causality. The apparent
beneficial effect of vaccination could, one might argue, be the result of
some third factor, such as poverty. Low-income people are at higher risk
of becoming infected with and dying from COVID-19, owing to a range of
factors, from housing conditions to types of employment. If they are also
less likely to get vaccinated, it could create the illusion that lack of
immunization is the problem. Yet the beauty of econometrics is that one
can control for third factors, such as the poverty rate or local
temperature, to isolate statistically the effect of vaccination rates.
But this does not fully resolve the causality question. There is also the
possibility that the simple observed correlation between vaccination and
mortality understates the true impact of the vaccines. After all, those
living in a high-risk context � say, near a transport hub � are more
likely to know people who have suffered from the coronavirus, and thus
might be more likely to get vaccinated. This �reverse causality� could
lead to an apparent � and excessive � positive correlation between
vaccination and death rates.And, in fact, this could partly explain why
earlier studies, conducted as recently as the beginning of June, did not
find a clear negative correlation. But, as the highly contagious Delta
variant gains traction among the unvaccinated, the correlation between
immunization and lower COVID-19 infection and death rates is
strengthening.Still, to have a chance of convincing the vaccine skeptics,
it is vital to disentangle causality from correlation. The key is to look
at variations in vaccination rates that have nothing to do with where and
how the coronavirus spreads � indeed, have nothing to do with the
coronavirus at all. In technical parlance, we need an �exogenous
instrument.�Party affiliation or voting patterns are an obvious choice.
Throughout the pandemic, Republican governors have been less likely than
their Democratic counterparts to support public-health measures, such as
mask mandates. Not surprisingly, Republican voters (45%) are less likely
than independents (58%) and Democrats (73%) to accept vaccines. In
counties where then-President Donald Trump won by a margin of 50
percentage points or more in the 2020 election, the vaccination rate was
below 25%, as of April 17.
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The �partisan gap� � which continues to widen � holds even after
accounting for income, race, and age, as well as population density and
the local infection and death rates. According to my calculations, when
controlling for the poverty rate and other relevant variables
(particularly age and temperature), a one percentage-point increase in the
share of a county�s residents over age 12 who were fully vaccinated as of
June 9 is associated with a death rate that was 0.05 lower per 100,000
inhabitants during the subsequent 30 days.
To ensure that the results are not distorted by reverse causality, I also
performed another calculation, based on the same data. Accounting for
variation in the vaccination decision attributable solely to partisan
political affinity � and controlling for variables like poverty � I found
the difference in the COVID-19 death rate to be 0.04 per 100,000
inhabitants.I used voting patterns not to target any particular group, but
rather to provide a better estimate of vaccine effectiveness on anyone.
But I hope that at least some skeptics notice that members of their
political �in-group� are dying at a higher rate, and decide to give
vaccination a chance. As Rochelle Walensky, the director of the US Centers
for Disease Control and Prevention, recently observed, �This is becoming a
pandemic of the unvaccinated.�