66 Finance & economics The EconomistNovember 14th 2020
F
or epidemiologists,2020 has been a trial by fire. Economists
should be able to relate; it was just over a decade ago that their
own practices and forecasts were subjected to the harsh glare of
the public eye in the aftermath of the global financial crisis. In-
stead the relationship between the two disciplines has been a testy
one. Some economists even questioned whether epidemiologists
were intellectually equipped for the trial. “How smart are they?
What are their average gre scores?” wondered Tyler Cowen of
George Mason University in April. The snootiness is unfortunate.
The challenges posed by the coronavirus pandemic—and those
that are still to come, as vaccines are distributed—cry out for co-
operation. But too often, when economists venture into other aca-
demic areas, their arrival often looks more like a clumsy invasion
force than a helpful diplomatic mission.
The two fields got off on the wrong foot early on in the pandem-
ic. Back then there was an acute need for models that predicted the
possible course of covid-19, in order to inform the policy response.
Epidemiologists, like economists, use different sorts of models in
their work, each subject to its own limitations and more useful in
some contexts than others. In March researchers at Imperial Col-
lege London used a model to calculate the potential death toll of
the virus, assuming that people and governments took no mea-
sures to stop its spread. The analysis concluded that perhaps
500,000 Britons and 2.2m Americans would die in such circum-
stances (roughly ten times as many as have died so far). The num-
bers frightened governments into taking drastic steps to mitigate
the spread of the virus, but they drew intense criticism, much of it
from economists. Detractors argued that the model’s assumptions
were unrealistic (a strange stone for an economist to throw). Peo-
ple would of course act to protect themselves from harm, they ar-
gued, meaning that the death toll would surely be much smaller.
The authors of the Imperial College study had been open about
this assumption, though, and even noted that it was unrealistic. In
a newly published essay in the Journal of Economic PerspectivesEl-
eanor Murray, an epidemiologist at Boston University, says econo-
mists misunderstood the aim of the model, which was to set out a
worst-case scenario as a baseline against which to estimate the ef-
fects of potential policy interventions. Criticisms of other model-ling approachesweresimilarly rooted in misinterpretation of
their intended audience and purpose, she reckons.
Given that building models is a favourite pastime of econo-
mists, the perception that epidemiologists’ efforts were not good
enough led many to dig into the data themselves. This too proved
problematic, writes Ms Murray. Drawing sound conclusions from
the available epidemiological data is hard when the scope of po-
tential uncertainty is unknown—because the share of covid-19
cases that are asymptomatic either cannot be determined or
changes as the virus spreads, for example. Such ambiguities neces-
sarily apply when dealing with a novel pathogen like the virus
which causes covid-19, a fact that economists unaccustomed to
dealing with epidemiological data may not have appreciated.
Rather than attempting to outdo the experts, Ms Murray writes,
economists ought to have taken advantage of specialisation, and
focused their efforts on questions epidemiologists are less
equipped to address.
This is a bit unfair. Yes, some modelling attempts by econo-
mists have been the work of dabblers. But the subfield of economic
epidemiology has been studying how social factors influence the
spread of a disease for decades. Much of the outpouring of recent
economic work on issues related to covid-19 has steered clear of
modelling its course, and focused instead on precisely those areas
where economists can better add value. Confounding uncertainty
notwithstanding, scholars have worked at great speed, producing
hundreds of papers evaluating policy measures, analysing the eco-
nomic costs associated with outbreaks and lockdowns, and as-
sessing how the pandemic is reshaping the global economy—work
that this newspaper has relied upon in its coverage of covid-19.
Still, economics could do better. Interdisciplinarity has long
been eyed with suspicion. Robert Solow, a Nobel prizewinner,
once dismissed critics of his profession by saying that, “When they
want economics to be broader and more interdisciplinary, they
seem to mean that they want it to give up its standards of rigour,
precision and reliance on systematic observation interpreted by
theory, and to go over instead to some looser kind of discourse.”
Even those scholars interested in wandering off-piste face incen-
tives not to collaborate with researchers in other fields, reckons
Tony Yates, an economist formerly of the University of Birming-
ham. For academics seeking tenure, publication in top economic
journals is of paramount importance. Co-operation with a non-
economist places some control over research in the hands of
scholars for whom acceptance by a top journal is less of a priority.
Economists’ forays into other disciplines therefore benefit much
less from knowledge-sharing across fields than is ideal.A lack of disciplines
All this is especially unfortunate, because epidemiologists’ chief
source of frustration in the pandemic is one that also bedevils the
economics profession. As Ms Murray notes, the epidemiological
community was unprepared for the way in which its policy recom-
mendations would be politicised and its public statements
warped by agents of misinformation. Economists should empath-
ise. Their efforts to explain complicated ideas to the masses, from
the virtues of trade to the need for bank bail-outs, have often foun-
dered. Such failures encourage economists to become more insu-
lar. But, as the pandemic has revealed, sometimes the effects of a
policy hinge on how well the public understands what is being
done and why. A profession that is more open to collaboration
might also learn from the communications struggles of others. 7Free exchange Field excursion
Economists have had a rocky relationship with epidemiologists this year. But there are gains to trade