Related Questions on Metaculus:

• Will there be a complete 4 year interval in which world output doubles, before the first 1 year interval in which world output doubles?
• Will there be a 4 year interval in which world output doubles before 2050?

As of 2018, it's taken about 16 years for the world economic output to double. So it might seem absurd to talk about it doubling in one or even four years. But there is a potential major change on the horizon: very advanced Artificial Intelligence.

An important consideration in how to approach the AI alignment problem is the speed of the takeoff from massively subhuman AI to massively superhuman AI. The effectiveness of capacity limitation, as well as the existence of fire alarms for AI safety, are heavily dependent on this, for example.

Paul Christiano suggests operationalising the takeoff speed in terms of economic growth. A slow takeoff is one where the economy doubles in four years before the first time it doubles in one year, and a fast takeoff is one where it does not. (See the same article for Christiano's list of arguments regarding fast vs. slow takeoff.)