By Bryan Caplan
This world contains mighty social forces that have worked wonders within the observed range. Top cases:
1. Industrialization. So far, industrialization has launched mankind from the ubiquitous poverty of the farmer age to the amazing plenty of the modern age.
2. Population growth. So far, population growth has greatly improved living standards by increasing the total number of idea creators, and hence the global rate of innovation.
3. Computers. So far, computers have made human existence not only markedly richer, but much more entertaining.
4. Nuclear physics. So far, nuclear physics has allowed the creation of cheap, clean energy. And it’s far from clear that the net body count of the nuclear bomb even exceeds zero. A conventional conquest of Japan probably would have exceeded the body counts of Hiroshima and Nagasaki.
5. Immigration. So far, immigration – especially from poor countries to rich countries – has lifted hundreds of millions of people and their descendants out of poverty, with no clear harm to host countries’ institutions.
Still, in each case, the “so far” proviso sounds ominous. Anyone given to morbid thinking can imagine that these so-far-wonder-working social forces are leading to utter disaster. Let the nightmares begin! Industrialization could lead to environmental apocalypse or global totalitarianism. Population growth could lead to mass famine. Computers could lead to ultra unfriendly Artificial Intelligence – the Terminator scenario. Nuclear physics could lead to all-out nuclear war. Immigration could destroy First World institutions, making the whole world into the Third World.
For the numerate, of course, the mere ability to weave nightmare scenarios is no reason to lift a finger. Probabilities are essential. How can we estimate these probabilities? In practice, most of us pick out a few “serious” nightmares on ideological grounds, and dismiss the rest as too silly to entertain. But that hardly seems like a reliable way to proceed.
How should we ballpark disaster probabilities? Think like superforecasters.
First step: Remember the base rate. Disasters are inherently rare. As I put it a decade ago:
The fact that we’ve gotten as far as we have shows that true disaster must be extremely rare.
Unless fears almost always failed to materialize, we’d already be back
in the Stone Age, or plain extinct. It’s overwhelmingly unlikely that
we’ve gotten lucky a million times in a row.
Second step: See how long the observed range has lasted. Centuries of success deserve heavy weight.
Third step: See how historically prevalent doom-saying about X has been. Why does this matter? Because it measures humans’ topic-specific propensity for paranoia. If everyone thought industrialization was fine until ten years ago, we should be more worried than if industrializationphobes started squawking in 1750.
Not good enough? If you’re morbid across the board, I’ve got nothing more to say – though I’m eager to bet you. If you’re selectively morbid, though, I’d like to know why the nightmares that keep you up at night are so much more compelling than the nightmares that put you to sleep.