The document discusses an article by economist Paul Krugman from 1992 where he reflected on the evolution of development economics as a discipline. Krugman noted that development economics was once not considered a valid field of study by economists. He examined the origins of development economics in 1943 with Paul Rosenstein-Rodan's paper arguing for massive investments in industry to spur employment and development. However, Rosenstein-Rodan's ideas were not taken seriously by economists due to its informal style that could not be modeled. The author draws parallels to medicine, questioning what currently marginalized ideas may become accepted in the future and what constitutes valid evidence in medicine today.

1. Comment
Offline: The evolution of ignorance
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The name Paul Krugman may lead you to think of the
celebrated economist who won a Nobel Prize in 2008
for his work on international trade. Or you may be
reminded of the prolific New York Times columnist who
regularly takes aim at the Republican Party. Economist
or columnist, they are, of course, one and the same
man. And if you read Krugman you will also know that
he projects formidable confidence, even certainty,
in his pronouncements. It was not always so. Once
Krugman was simply a young academic trying to forge
a reliable reputation, a man struggling to be heard by
the popular mainstream of his discipline. 20 years ago,
that Paul Krugman was less confident, more reflective,
and, in many ways, a great deal more compelling. His
subject back then was what counts as valid evidence. His
meditations on what we know—or choose to know—are
pertinent to all areas of inquiry today, including medicine.
*
pidjoe
Walter Zerla
In 1992, Krugman gave the Ohlin Lectures at the
Stockholm School of Economics. The “fuzzy, slight”
arguments he put forward in these lectures were
eventually revised and published in a short book,
Development, Geography, and Economic Theory (1995).
His starting point was that development economics
was a field that did not exist. To anyone interested
in global health today, this statement will seem
incomprehensible. Development economists are now
international celebrities—think of Jeff Sachs, Amartya Sen,
Joseph Stiglitz. But, a generation ago, Krugman lamented
that “very few economists would now presume to offer
grand hypotheses” about the determinants of successful
nations. Krugman sought to examine the history of this
failed discipline. Its “golden age” began in 1943 with a
paper by Paul Rosenstein-Rodan, unpromisingly entitled
“Problems of industrialisation of Eastern and SouthEastern Europe”. This work can still be read profitably by
those concerned with understanding the origins of (and
justification for) international aid. Rosenstein-Rodan
argued that, “The aim of industrialisation...is to [create]
productive employment for the agrarian population.” This
objective could be achieved through massive investments
in industry. He admitted that such an approach would be
“a tremendous task, almost without historical precedent”.
It became known as “The Big Push”. But slowly the idea,
856
and the emerging field, faded away. Economists turned
their backs on questions about how to alleviate world
poverty. Why? Was it because, as Krugman confesses,
“economists are notoriously uninterested in how people
actually think or feel”? No. The reason was more prosaic.
There were no models for economists to experiment with.
If you read Rosenstein-Rodan’s paper today, you will find
that it is perfectly intelligible. This was its great weakness.
Its discursive and informal style meant that economists
could not—would not—take it seriously.
*
Why does this example matter beyond the narrow
boundaries of development economics? Because the
larger question Krugman asks is extremely relevant to
health: what makes an idea acceptable or unacceptable?
The answer in economics was something you can model
(“Economic theory is essentially a collection of models”,
wrote Krugman). What is the answer in medicine? In
economics, Krugman describes his field in the 1990s as
“outcast literature”. And yet just 16 years later he received
a Nobel Prize for that same “outcast” work. What ideas are
presently marginalised in medicine today that might one
day, perhaps within the next two decades, be prize-winning
insights? Krugman is tough on his fellow economists. Their
unwillingness to think about what they could not model
“led them to ignore ideas that turn out, in retrospect, to
have been very good ones”—”the insistence on models that
meet the standards of rigour in mainstream economics can
lead to neglect of clearly valuable ideas”. In medicine, we
might ask a similar question. What good ideas are around
today that are “strangely unsuccessful” in influencing
our thinking? At one point, Krugman writes that “to do
development theory, one must have the courage to be
silly”. Perhaps we in medicine should collect a list of today’s
unacceptable (and “silly”) thoughts and theories. Perhaps
we should curate this list carefully, checking and rechecking
the value of each “silly” idea so that important discoveries
are neglected for the least possible time. Krugman’s lesson
is “not to let important ideas slip by just because they
haven’t been formulated your way”. Read your journals
with care, but with an open mind too.
Richard Horton
richard.horton@lancet.com
www.thelancet.com Vol 383 March 8, 2014