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?
Acknowledgments
This research would not have been possible without the generous support of the Musk Foundation and the Long-Term Future Fund. We thank Walter Frick, Michael Page, Terry Murray, David Budescu, Barb Mellers, Elie Hassenfeld, Philipp Schoenegger, and Pavel Atanasov for their thoughtful feedback and comments. We are also grateful for the many people who reviewed earlier drafts of this report. We greatly appreciate the assistance of Amory Bennett, Kaitlyn Coffee, Adam Kuzee, Avital Morris, Fiona Pollack, Coralie Consigny, Arunim Agarwal, and Rumtin Sepasspour throughout the project. Lastly, we extend our gratitude to our research participants for their invaluable contributions.
