Three wild speculations from amateur quantitative macrohistory

Note: As usual, these are my personal guesses and opinions, not those of my employer.

In How big a deal was the Industrial Revolution?, I looked for measures (or proxy measures) of human well-being / empowerment for which we have “decent” scholarly estimates of the global average going back thousands of years. For reasons elaborated at some length in the full report, I ended up going with:

1. Physical health, as measured by life expectancy at birth.
2. Economic well-being, as measured by GDP per capita (PPP) and percent of people living in extreme poverty.
3. Energy capture, in kilocalories per person per day.
4. Technological empowerment, as measured by war-making capacity.
5. Political freedom to live the kind of life one wants to live, as measured by percent of people living in a democracy.

(I also especially wanted measures of subjective well-being and social well-being, and also of political freedom as measured by global rates of slavery, but these data aren’t available; see the report.)

Anyway, the punchline of the report is that when you chart these six measures over the past few millennia (data; zoomable), you get a chart like this (axes removed for space reasons):

(And yes, there’s still a sharp jump around 1800-1870 if you chart this on a log scale.^[1])

Basically, if I help myself to the common (but certainly debatable) assumption that “the industrial revolution” is the primary cause of the dramatic trajectory change in human welfare around 1800-1870,^[2] then my one-sentence summary of recorded human history is this:

Everything was awful for a very long time, and then the industrial revolution happened.

Interestingly, this is not the impression of history I got from the world history books I read in school. Those books tended to go on at length about the transformative impact of the wheel or writing or money or cavalry, or the conquering of this society by that other society, or the rise of this or that religion, or the disintegration of the Western Roman Empire, or the Black Death, or the Protestant Reformation, or the Scientific Revolution.

But they could have ended each of those chapters by saying “Despite these developments, global human well-being remained roughly the same as it had been for millennia, by every measure we have access to.”^[3] And then when you got to the chapter on the industrial revolution, these books could’ve said: “Finally, for the first time in recorded history, the trajectory of human well-being changed completely, and this change dwarfed the magnitude of all previous fluctuations in human well-being.”

This is especially clear if we look at at GDP per capita, for which we have especially detailed (but still quite uncertain!) estimates. Here’s GDP per capita (PPP) from 1-1800 CE:

If this is roughly accurate, then the drop in GDP per capita from 1000 to 1300 probably felt pretty awful to those living at the time, and the subsequent recovery probably felt pretty great. But these sorts of fluctuations are so small compared to what happened after the industrial revolution that they show up as a flat line when we include the post-industrial era:

That said, the long-run estimates I rely on are pretty uncertain, and my particular choice of measures to capture “well-being” is obviously questionable (and to some, no doubt objectionable), so I will still refer to the basic picture presented above as “speculative.”^[4]

Thus I’ll say my first speculation from my brief expedition in “quantiative macrohistory” is this:

Human well-being was pretty awful by modern standards until the industrial revolution, after which most things we care about got vastly better in the span of a century or two.

But that is probably not a surprising claim to most readers of this blog, especially those who have studied economic history.

Fortunately, my second speculation is probably even more speculative and controversial:

If we had all the data, and we did a factor analysis of “what mattered for human well-being in recorded history,” I suspect most of the variance in human well-being would be explained by a primary factor for productivity, and a secondary factor for political freedom.

The first factor probably isn’t surprising. Technological progress, energy capture, other aspects of productivity, and wealth all feed on each other and are in some cases hard to even distinguish, and they all generally improve physical health and many other things we care about.

But why do I suggest political freedom as a plausible second factor, given that “percent of people living in a democracy” tracks so closely with all the other measures of well-being covered above? Largely, it’s because I think “percent of people enslaved” is a more important measure of political freedom than democracy is, and while I wasn’t able to collect/guess enough data points to chart global slavery over time, I read enough of the history of slavery to get the impression that if I could chart it, it might not track that well with the other measures discussed above — at least, not until about 1900.

Instead of being well-represented by a simple hockey-stick, my rough guess is that “percent of people enslaved”…

• …was quite low near the dawn of recorded history, and gradually rose until about 500 CE,
• held steady or diminished somewhat from 500-1500, and then
• exploded upward during the international slave trade, and finally
• dropped precipitously as the anti-slavery movement made its way around the world.

Anyway, if we run with this wild speculation, then we might conclude that to improve human well-being going forward, there are basically two great battles to be fought: one for greater productivity, and the other for greater political freedom. Except, that hasn’t actually been the case since the invention of nuclear weapons, due to existential risk.

Perhaps the biggest reason to be skeptical of this 2nd speculation is that it’s based on measures for which I was able to find long-run data, and that means it can’t make use of data on various aspects of subjective well-being (e.g. moment-to-moment happiness, or sense of meaning) or aspects of social well-being (e.g. sense of community). Perhaps those would be clear major factors if we had long-run data for them. But perhaps not!^[5]

My third speculation is a happier thought:

Fortunately, it seems it would take a lot of deaths — maybe 15% of world population or even more — to knock civilization off its current positive trajectory (via deaths, anyway).

This speculation results from cataloguing the deadliest events in history, and finding that the worst of them (the Black Death and Genghis Khan) each killed about 10% of world population, and the deadliest event since our current positive trajectory began (with the industrial revolution) was the World War I + Spanish flu double whammy, which killed 4.1% of world population. At a glance, none of these events seem to have “come close” to prompting a downward spiral akin to a “negative industrial revolution” or (in the case of WWI+flu) knocking us off our current positive trajectory. Perhaps this is slightly reassuring about whether (say) a biosecurity disaster that killed 100 million people (<1% of world population) could be an existential threat to humanity (as opposed to being merely completely horrifying, worse than the Holocaust).

(Please remember that there are numerous caveats, clarifications, etc. in the full report; please consider reading them before lambasting my wild speculations or their underlying assumptions. Also, I think these speculations, especially the latter two, are pretty unstable: I don’t think it would take that much study and debate to make me heavily revise them, or abandon them altogether.)