Friday, July 3, 2020

The ten worst predictions in history: learning from past mistakes

  Ugo Bardi experiments with new predictive methods.

This post was inspired mainly by the shock I had with the various failed attempts to predict the outcome of the Covid-19 epidemic. It was truly a sobering experience: bad predictions, clueless politicians, arrogant scientists, idiotic journalists, and more. It made me doubt of the usefulness of models in general. I think we are doing several (too many) things wrong with the way we use models and (sometimes) we trust them. I'll be discussing more on this subject in future posts, for the time being, here is a list of failed predictions that I think can teach us something.

1. Coronavirus Deaths. In 2020, the model developed in large part by Neil Ferguson at the Imperial College in London was the main element that led the British government to engage in a strict "lockdown" policy to avoid the hundreds of thousands (perhaps millions) of deaths that the model predicted as a result of the COVID-19 disease. Most European States followed suit. It is still early to evaluate how the real world followed the model but, if we look at the result proposed in the "Report n. 9", we see that the model was clearly overly pessimistic. The authors of the model defended their work saying that their prediction of doom was just one of several scenarios, which is correct, but weak as a defense. In the future, we'll be able to say if Europeans truly wrecked their economies for nothing but, for the time being, the coronavirus experience can be seen as a sobering experience on the limits of the models as predictive tools.

2. The Population Bomb. In 1968, Paul Erlich and his wife Anne wrote a book titled "The Population Bomb." To say that it was catastrophistic is a little of an understatement. It is known to have contained the sentence  In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. As we all know, that didn't happen. Instead, the 1970s ushered an era of apparent abundance in the food supply that led to a rapid increase in the human population. Yet, The Erlichs' prediction may not have been so bad, at least in qualitative terms. In reality, the current population is so large that if a new famine comes, it will cause the death of not just "hundreds of millions of people" but, likely, billions of them. You might argue that the present situation is much more dangerous in terms of risks of famines than it was half a century ago, when the world's food supply was not so critically linked to the supply of fossil fuels as it is today. This story illustrates once again how difficult it is to use models for quantitative predictions, even though they may be qualitatively good. 

3. Julian Simon's 7 billion years of prosperity. In 1994, Julian Simon wrote, "We now have in our hands in our libraries, really the technology to feed, clothe, and supply energy to an ever-growing population for the next 7 billion years... " (Myers, N., and Julian Simon. (1994): Scarcity or Abundance, New York: Norton.). In reality, we are reaching the limits of our capabilities of doing that just now. We may conclude that Simon was off of some 7 billion years. It was a ridiculous idea from the beginning but, at least, it shows to us that there is no limit to how wrong you can be with your predictions!

4. Too much oil. In 1999, the respectable (so to say) "Economist" magazine published a leader titled "Drowning in Oil" where it was argued that the prices of oil were going to become so low that they would damage the economy, literally "drowning it in oil." The authors went on proposing that the oil price could soon go down to 10 dollars per barrel and perhaps even to 5 dollars per barrel. Needless to say, the trend was exactly the opposite, with oil prices starting a sustained rally that took them all the way up to some 150 dollars per barrel in 2008. Curiously, oil prices did plunge, briefly, to "negative" values in 2020, but if this is what the Economist authors were thinking, they were 20 years off with their prediction! This story is just one of the many disasters that ensued when someone tried to predict the vagaries of prices, even in a not so remote future. Prices are so strictly linked to human whim and perception that it seems to be simply impossible to predict them.

5. The Great Horse Manure Crisis. It is said that, in 1894, The Times newspaper predicted… “In 50 years, every street in London will be buried under nine feet of horse manure.” This prediction was obviously wrong, as reported and it is often used to poke fun at those silly catastrophists. But, in reality, there is no trace in the archives of "The Times" that it was ever uttered, it is a piece of fake news.  This story illustrates that you can be wrong even with a non-existing prediction!

6. The Wargame that lost the war for Japan.  It is known that, before the start of WW2, the Japanese admiralty engaged in a series of simulation games destined to determine the possible outcome of a war against the United States. It is reported that when one of these simulations was leading to a crushing defeat for the Japanese forces, the umpires (or perhaps Admiral Yamamoto himself) ordered two Japanese carriers "refloated," so that the game ended with a Japanese victory. The story of the refloated carriers is probably a legend, at least in part, but it is true that the Japanese wouldn't have engaged in the war against the US hadn't they had some kind of evidence that they could have won. It shows how dangerous it is to trust models for systems that have a binary outcome.

7. The Peace Dividend. In the 1990s, with the Soviet Union defeated and gone, some people thought that there was no more justification for the gigantic and cumbersome military apparatus that the Western Empire (officially) maintained as a defense against Communism. So, they thought it could be dismantled and the money saved distributed to the people. That was called the "peace dividend." Alas, that idea now looks as remote as the fall of the Roman Empire. Soon, there came the 9/11 attacks and the military apparatus was beefed up even more. Those who had proposed the idea of a peace dividend never realized that nobody ever made money on peace. And, as you see, it is rarely a good idea to think that people will behave in ways that make them lose money.

8. Nibiru. The story of the planet Niburu that should impact on Earth appeared for the first time in 1995, diffused by Nancy Lieder. The first predictions said the cataclysm should have been in 2003, but the best-known prediction indicated 2012 as the fatal year, something that gained a certain notoriety and a number of followers. Of course, nothing happened in 2012, so the date of the impact has been progressively moved onward, but the whole story seems to have lost interest -- as it should have. At least, this story tells us that wrong predictions may be a lot of fun and cause little damage. 

9. The Solow-Swan model. In the 1950s, Robert Solow proposed a model for the US economy based on a simple formula that generated exponential growth. The model came to be known as the "Solow-Swan" model.  There was no term in the model that accounted for the possibility of a decline or a collapse so that it was generally interpreted by economists as implying that there were no limits to growth and that the economy could be growing forever. Today, most of the choices made by politicians and decision-makers all over the world seem to be based on this model, trying, for instance, to "restart the economy" after the SARS-Cov2 epidemic by means of stimulating more consumption. That, of course, is going to make things worse if the crisis is caused by a dearth of natural resources, as it is the case. This model shows us how you can do tremendous damage to humankind even by means of just a one-line equation.

10. The second coming (or the parusia). If you read the texts written by the early Christians, Paulus, and others, it is rather clear that they were expecting the "second coming" of Jesus Christ during their lives. That, of course, didn't happen and Christians have been waiting for this dramatic event for a long time, and they are still waiting for it, sometimes under different names such as the "rapture." We cannot exclude that one of these days we'll hear a booming voice coming from the sky telling us that "The Day of Judgement has come" -- but so far that didn't happen. So, this prediction turns out to have been wrong of at least 2000 years (so far). But Christians are still waiting for the second coming and so we can conclude that predictions with no well-defined time frame can never be disproved!


Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)