Forecasting existential risks

Abstract

The Existential Risk Persuasion Tournament (XPT) aimed to produce high-quality forecasts of the risks facing humanity over the next century by incentivizing thoughtful forecasts, explanations, persuasion, and updating from 169 forecasters over a multi-stage tournament. In this first iteration of the XPT, we discover points where historically accurate forecasters on short-run questions (superforecasters) and domain experts agree and disagree in their probability estimates of short-, medium-, and long-run threats to humanity from artificial intelligence, nuclear war, biological pathogens, and other causes. We document large-scale disagreement and minimal convergence of beliefs over the course of the XPT, with the largest disagreement about risks from artificial intelligence. The most pressing practical question for future work is: why were superforecasters so unmoved by experts’ much higher estimates of AI extinction risk, and why were experts so unmoved by the superforecasters’ lower estimates? The most puzzling scientific question is: why did rational forecasters, incentivized by the XPT to persuade each other, not converge after months of debate and the exchange of millions of words and thousands of forecasts?