As I’ve discussed before, including in my book, the history of humanity so far can be roughly summarized as a sequence of three exponential growth modes: foragers with culture started a few million years ago, farming started about ten thousand years ago, and industry starting a few hundred years ago. Doubling times got progressively shorter: a quarter million years, then a millennia, and now fifteen years. Each time the transition lasted less than a previously doubling time, and roughly similar numbers of humans have lived during each era.
Before humans, animal brains brains grew exponentially, but even more slowly, doubling about every thirty million years, starting about a half billion years ago. And before that, genomes seem to have doubled exponentially about every half billion years, starting about ten billion years ago.
What if the number of doublings in the current mode, and in the mode that follows it, are comparable to the number of doublings in the last few modes? What if the sharpness of the next transition is comparable to the sharpness if the last few transitions, and what if the factor by which the doubling time changes next time is comparable to the last few factors. Given these assumptions, the next transition will happen sometime in roughly the next century. Within a period of five years, the economy will be doubling every month or faster. And that new mode will only last a year or so before something else changes.
To summarize, usually in history we see relatively steady exponential growth. But five times so far, steady growth has been disturbed by a rapid transition to a much faster rate of growth. It isn’t crazy to think that this might happen again.
Plausibly, new faster exponential modes appear when a feedback loop that was previously limited and blocked becomes is unlocked and strong. And so one way to think about what might cause the next faster mode after ours is to look for plausible feedback loops. However, if there thousands of possible factors that matter for growth and progress, then there are literally millions of possible feedback loops.
For example, denser cities should innovate more, and more innovation can find better ways to make buildings taller, and thus increase city density. More better tutorial videos make it easier to learn varied skills, and some of those skills help to make more better tutorial videos. We can go all day making up stories like these.
But as we have only ever seen maybe five of these transitions in all of history, powerful feedback loops whose unlocking causes a huge growth rate jump must be extremely rare. The vast majority of feedback loops do not create such a huge jump when unlocked. So just because you can imagine a currently locked feedback loop does not make unlocking it likely to cause the next great change.
Many people lately have fixated on one particular possible feedback loop: an “intelligence explosion.” The more intelligence a creature is, the more it is able to change creatures like itself to become more intelligent. But if you mean something more specific than “mental goodness” by “intelligence”, then this remains only one of thousands of possibilities. So you need strong additional arguments to see this feedback loop as more likely than all the others. And the mere fact that you can imagine this feedback being positive is not remotely enough.
It turns out that we already know of an upcoming transition of a magnitude similar to the previous transitions, scheduled to arrive roughly when prior trends led us to expect a new transition. This explosion is due to labor-from-factories.
Today we can grow physical capital very fast in factories, usually doubling capital on a scale ranging from a few weeks to a few months, but we grow human workers much more slowly. Since capital isn’t useful without more workers, we are forced to grow today mainly via innovation. But if in the future we find a way to make substitutes for almost all human workers in factories, the economy can grow much faster. This is called an AK model, and standard growth theory says it is plausible that this could let the economy double every month or so.
So if it is plausible that artificial intelligence as capable as humans will appear in the next century or so, then we already know what will cause the next great jump to a faster growth mode. Unless of course some other rare powerful feedback loop is unlocked before then. But if an intelligence explosion isn’t possible until you have machines at least as smart as humans, then that scenario won’t happen until after labor-from-factories. And even then it is far from obvious that feedback can cause one of the few rare big growth rate jumps.