Jul 5, 2018 8:00 AM

Welcome to the Highly Probable World of Improbability

Humans love to read meaning into the improbable, even when such events—from Germany's World Cup loss to Alexandria Ocasio-Cortez's congressional win—happen frequently.

In The Hitchhiker’s Guide to the Galaxy, the problem of intergalactic travel is ultimately solved by suspending an atomic vector plotter in a nice hot cup of tea. The tea, it turns out, is a strong producer of Brownian Motion: The molecules of water are moving pseudo-randomly, and any given specific configuration of those molecules is highly improbable. The vector plotter takes the improbability of that particular nice hot cup of tea, converts it into the identical improbability of intergalactic travel, and, presto, spaceships can travel, instantly, through every point of every conceivable universe.

To put it another way: Highly improbable events are all around us. Those events can make for extremely exciting sport competitions — after running 10,000 simulations, for instance, a team of 18 analysts from Swiss banking giant UBS determined that Germany, with a 91 percent chance of making it through to the round of 16, was by far the most likely country to win the World Cup. Instead, Germany crashed out at the bottom of its group, losing not only to Mexico but also to South Korea.

At roughly the same time, in June’s midterm primaries, 28-year-old political neophyte Alexandria Ocasio-Cortez spectacularly dethroned Joseph Crowley, the powerful congressman who chaired not only the Queens County Democratic Party but also the House Democratic Caucus. Her thumping victory was a direct consequence of another highly improbable result — the 2016 election of Donald Trump as US president. Trump’s election came in the wake of an electoral upset across the pond — the Brexit referendum — which came as such a surprise that the most sophisticated prediction mechanism on the planet, the global foreign-exchange market, was blindsided in the middle of the British night. If you were one of the small group of hedge funds that bet in the right direction, you ended up making well over $100 million in the space of a few hours.

Humans love to read meaning into the unexpected and the improbable, even where there is none. As the title of Nassim Nicholas Taleb’s best seller has it, we’re fooled by randomness. When Germany fails to make it out of the group stage of the World Cup, the pundits say it turned out to be a weaker team than anybody thought; when Ocasio-Cortez beats Crowley, we say that’s because she ran a powerful grassroots campaign that was largely invisible to the media elite; when Trump is elected president or when Britain votes to leave the EU, that’s because of ... [insert any one of a thousand explanations here].

None of these narratives is wrong, exactly; they just tend to overlook the simple fact that improbable events happen on a regular basis, and that for every improbable event that happens, there are dozens which don’t. In certain artificial contexts, the frequency of improbable events can even be quantified: If you’re playing backgammon or craps, for instance, you know that you’ll get double ones one time in every 36 rolls, on average. If you roll a pair of dice a hundred times and never get double ones, you might not be surprised, but at the same time something fishy is going on.

In the real world, probabilities tend to be Bayesian rather than frequentist — which is to say, their improbability is not something that can be measured empirically, but is rather a function of the available evidence and the direction that evidence points. You can’t measure the probability of outcomes in the World Cup or an election by re-running the same experiment thousands of times, since these are events that are played only once.

Still, there’s nothing inevitable about their outcome, and it remains important and true to be able to say that Germany was probably going to win their group, that Crowley had every reason to expect an easy victory, and that any presidential election where one candidate gets 4 million more votes than her opponent is overwhelmingly likely to result in that candidate’s victory. The recriminations that invariably follow an improbable event all too often ascribe an inevitability to a result which wasn’t inevitable at all and which in truth can most honestly be credited simply to bad luck.

In many ways, the really improbable event of recent decades was the manner in which so much of the world experienced stability and predictability. What was the probability that we could, collectively, have created such an unprecedented quantity of wealth, health, and prosperity? The late Hans Rosling astonished audiences worldwide by showing them the enormous gains that humanity has made; economists tend to work from the assumption that nearly every economy will grow in nearly every year, and that the rare periods of shrinkage, or recession, are anomalies which can generally be blamed on misguided government policy. The growth assumption is generally true today, but would have been hilariously false for most of human history. Steady, compounding economic growth is a relatively new phenomenon, and one that is almost impossible to grasp instinctively.

Perhaps human intuition has something important to tell us here: That those audiences were right to be astonished by Rosling’s statistics, and that it’s perfectly normal for things to go down as often as they go up. Certainly the sweepingly new political enterprises being installed in countries from China to Hungary to Mexico — not to mention the US — are explicitly designed to upend the old system and replace it with something radically different. Disorder and unpredictability used to be the result of political mistakes and miscalculations; increasingly they’re a desired outcome of political leaders, with Donald Trump gleefully playing the role of chaos monkey in chief.

The current world is one which has lost the probabilistic dampeners we all got used to growing up. We find ourselves immersed, much like Douglas Adams’s atomic vector plotter, in a soup of improbability—a place where we have to expect the unexpected. Such a world rewards resilience and improvisation; it naturally defeats well-laid plans.

The next time something improbable happens, then, don’t kick yourself for failing to see it coming, and don’t kid yourself that it was in any way inevitable. The best you can do is recalibrate and remain nimble. Because no matter what universe you find yourself in today, it’s very likely to be significantly different tomorrow.