Against GDP as a metric for timelines and takeoff speeds

Abstract

Or: Why AI Takeover Might Happen Before GDP Accelerates, and Other Thoughts On What Matters for Timelines and Takeoff Speeds [Epistemic status: Strong opinion, lightly held] I think world GDP (and economic growth more generally) is overrated as a metric for AI timelines and takeoff speeds. Here are some uses of GDP that I disagree with, or at least think should be accompanied by cautionary notes: * Timelines: Ajeya Cotra thinks of transformative AI as “software which causes a tenfold acceleration in the rate of growth of the world economy (assuming that it is used everywhere that it would be economically profitable to use it).” I don’t mean to single her out in particular; this seems like the standard definition now. And I think it's much better than one prominent alternative, which is to date your AI timelines to the first time world GDP (GWP) doubles in a year! * Takeoff Speeds: Paul Christiano argues for Slow Takeoff. He thinks we can use GDP growth rates as a proxy for takeoff speeds. In particular, he thinks Slow Takeoff ~= GWP doubles in 4 years before the start of the first 1-year GWP doubling. This proxy/definition has received a lot of uptake. * Timelines: David Roodman’s excellent model projects GWP hitting infinity in median 2047, which I calculate means TAI in median 2037. To be clear, he would probably agree that we shouldn’t use these projections to forecast TAI, but I wish to add additional reasons for caution.