In the extreme scenario, AI is more productive than humans at the vast majority of knowledge-work tasks. It does nearly all of them autonomously, and it creates essentially no new knowledge tasks for people. This scenario would likely require recursively self-improving AI, adopted quickly for knowledge work.
As AI diffuses, annual GDP growth rates reach 15% a year, leading the economy to double in size every 4.5 years. As a society, we’re far richer than we’ve ever been, but many fewer workers have jobs in knowledge work, and unemployment has risen beyond typical recessionary levels.
Mass automation will be disastrous for GDP in service economies. Service economies exist to provide services to other people who also provide services. If the services themselves get automated, you don't need that massive inefficient system to support service-providing workers anymore. GDP goes to zero.
I believe lot of "service" jobs are fundamentally make up work. Or not actually productive. Just there because it can be afforded. Or someone decided that it is "needed". Some amount of it produces net negative value. Some neutral and lot probably value we could even manage without it. Actual productive value is probably not that big part.
Now replace all that and you still produce same overall. Not more actual physical stuff.
