>Blathering talk surrounds us, but I will take no part in it. My word is my bet; I will always put my money where my mouth is. When challenged, I will bet on my words, refine them, or recant. When no one is present to challenge me, I will weigh my words and thoughts as if my fellow oath-takers were listening.

*—Caplan's [The Bettor's Oath](https://www.econlib.org/archives/2012/05/the_bettors_oat.html)*

George Mason University economics professor [Bryan Caplan](https://twitter.com/bryan_caplan?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Eauthor) is a proponent of betting—as epistemic tool and as accountability mechanism. He maintains a public [inventory of wagers](https://docs.google.com/document/d/1qShKedFJptpxfTHl9MBtHARAiurX-WK6ChrMgQRQz-0/edit) detailing a ([for now](https://www.metaculus.com/questions/5695/when-will-bryan-caplan-lose-a-bet/)) unbroken winning streak reaching back nearly two decades. 

Forecast in our new **[Bryan Caplan Collection](https://www.metaculus.com/project/caplan/)** to predict the outcomes of Caplan's bets on topics like explosive economic growth from AI, India's fertility rate, climate change, and more.

### [Learn more and start forecasting on the below and other questions](https://www.metaculus.com/project/caplan/)

* #### [Will Bryan Caplan win his bet on Iran acquiring a nuclear weapon?](https://www.metaculus.com/questions/21856/iran-has-no-nuclear-weapon-on-july-31-2025/)

* ####[Will Bryan Caplan win his bet on a climate change pause?](https://www.metaculus.com/questions/21965/global-warming-pause-2015-2029/)

* #### [Will Bryan Caplan win his bet on India's fertility rate?](https://www.metaculus.com/questions/21918/2032-2033-india-fertility-rate/)


**We're grateful to Bryan Caplan for his involvement in this series.**