I generally take the view that the Industrial Revolution was the most important event in history. Before, life was nasty, brutish and short; afterwards,
economic welfare hit its “hockey stick” moment. But in
this fascinating essay Scott Alexander lays out the (speculative) case that the industrial revolution wasn’t a discontinuity at all. If you chart the log time GDP has taken to double in each year over a multi-millennia period, you actually get a straight line - no discontinuity.
The argument is that economic growth comes from new ideas - and new ideas come from population growth (more people = more ideas). History is then a race between population growth and economic growth: until the industrial revolution,
per capita income didn’t increase. This was a classic
Malthusian trap: “productivity produces people, not prosperity”. Around the industrial revolution, per capita income started to rise, which allowed population to rise and, in turn, so did the rate of growth - but without breaking the “time to doubling” trend.
In this telling, the real discontinuity takes place not in ~1750, but in 1960. This is when the years moves, depressingly, off the trend line and towards stagnation. Why? Because people started to use their wealth to
reduce the number of children they have, so there’s been
no increase in the number of ideas generated. There was some substitution of humans by machines, which helped, but as Alexander says, “tractors can’t invent things”. AI might be more productive than tractors in this respect - but we’re not there yet.