Economists are currently being taken to task for the inaccuracy of their forecasts. Some of their most critical voices have come from the natural sciences, where the commentary has been mocking and at times malicious, especially when it comes to assessing research activities in the field of economics. Yet it’s easy to turn the tables: erroneous predictions in the natural sciences are legion and their consequences are, in all likelihood, much more costly than those caused by the misjudgements of economists.

Some of the criticism directed at economists was sparked during the severe recession of 2009. At the time, a number of economists in academics and in the field made predictions that in retrospect would seem needlessly pessimistic. For instance, they projected an L-shaped recession, but the actual recession turned out to be more V-shaped. Yet when it comes to pessimism, natural scientists beat the pants off economists. Epidemiologists are a great example. As Walter Krämer writes in Die Angst der Woche (2011), epidemiologists have become “a self-service store for fear mongers.”

To forestall potential misunderstandings from the start: the examples I will provide below involve, fortunately, nothing more than erroneous predictions, no different in principle from faulty economic forecasts. My point is not to stigmatize natural scientists for making errors, but to call their attention to the glass houses from which they throw stones at economists.

Surely the reader will recall during the E. coli (Ehec) outbreak some months ago when the highly respected Robert Koch Institute in Berlin warned people against eating cucumbers, tomatoes, and lettuce. Soon after, the health and consumer protection agency in Hamburg announced that the city’s Institute for Hygiene and Environment had identified the culprit: cucumbers from Spain. Within days, though, cucumbers were exonerated. Still, the losses suffered by farmers in Germany alone amounted to millions and millions of euros.  

To provide another example: In 2000 news that mad cow disease had been discovered in the United Kingdom reached Germany and triggered hysterical reactions. Healthy animals in both countries were slaughtered en masse. According to a subsequent hearing, German agencies ultimately spent some 1.5 billion euros during the outbreak – on culling, on unneeded testing, and on measures to stabilise the beef market. Yet the number of documented cases of mad cow disease, or BSE, were minimal, and, fortunately, there were no fatalities in Germany. “Perhaps,” as Walter Krämer put it in the Handelsblatt, “the hysteria surrounding BSE, which the media were mainly responsible for but which some natural scientists also helped flame, killed more people than the disease itself. Consider, say, farmers in the United Kingdom who committed suicide after their livelihoods were ruined by the BSE panic.”

The bird flu discovered in Asia also set off global panic. The World Health Organization issued a pandemic alert and one of its prominent experts was reported as predicting anywhere between 5 and 150 million fatalities. The real number of deaths came to 300 worldwide, and zero in Germany. The 2009 swine flu pandemic was more serious, but far less severe than officials – and scientists – initially feared. In Germany there were around 250 fatalities. The costs of protective measures in Germany amounted to more than several hundred million euros. Up to 40 million vials of the vaccination Pandemrix, valued at 250 million euros, had to be destroyed because only a fraction of the vials stockpiled were ever used. This is not the fault of politicians. Had they not taken these measures, and things had turned out as bad as epidemiologists predicted, they would have been accused of reckless negligence.