Yudkowsky Contra Christiano On AI Takeoff Speeds

In 2008, thousands of blog readers - including yours truly, who had discovered the rationality community just a few months before - watched Robin Hanson debate Eliezer Yudkowsky on the future of AI.

Robin thought the AI revolution would be a gradual affair, like the Agricultural or Industrial Revolutions. Various people invent and improve various technologies over the course of decades or centuries. Each new technology provides another jumping-off point for people to use when inventing other technologies: mechanical gears → steam engine → railroad and so on. Over the course of a few decades, you’ve invented lots of stuff and the world is changed, but there’s no single moment when “industrialization happened”.

Eliezer thought it would be lightning-fast. Once researchers started building human-like AIs, some combination of adding more compute, and the new capabilities provided by the AIs themselves, would quickly catapult AI to unimaginably superintelligent levels. The whole process could take between a few hours and a few years, depending on what point you measured from, but it wouldn’t take decades.

You can imagine the graph above as being GDP over time, except that Eliezer thinks AI will probably destroy the world, which might be bad for GDP in some sense. If you come up with some way to measure (in dollars) whatever kind of crazy technologies AIs create for their own purposes after wiping out humanity, then the GDP framing will probably work fine.

For transhumanists, this debate has a kind of iconic status, like Lincoln-Douglas or the Scopes Trial. But Robin’s ideas seem a bit weird now (they also seemed a bit weird in 2008) - he thinks AIs will start out as uploaded human brains, and even wrote an amazing science-fiction-esque book of predictions about exactly how that would work. Since machine learning has progressed a lot faster than brain uploading has, this is looking less likely and probably makes his position less relevant than in 2008. The gradualist torch has passed to Paul Christiano, who wrote a 2018 post Takeoff Speeds revisiting some of Hanson’s old arguments and adding new ones.

(I didn’t realize this until talking to Paul, but “holder of the gradualist torch” is a relative position - Paul still thinks there’s about a 1/3 chance of a fast takeoff.)

Around the end of last year, Paul and Eliezer had a complicated, protracted, and indirect debate, culminating in a few hours on the same Discord channel. Although the real story is scattered over several blog posts and chat logs, I’m going to summarize it as if it all happened at once.

Gradatim Ferociter

Paul sums up his half of the debate as:

There will be a complete 4 year interval in which world output doubles, before the first 1 year interval in which world output doubles. (Similarly, we’ll see an 8 year doubling before a 2 year doubling, etc.)

That is - if any of this “transformative AI revolution” stuff is right at all, then at some point GDP is going to go crazy (even if it’s just GDP as measured by AIs, after humans have been wiped out). Paul thinks it will go crazy slowly. Right now world GDP doubles every ~25 years. Paul thinks it will go through an intermediate phase (doubles within 4 years) before it gets to a truly crazy phase (doubles within 1 year).