One of the earliest editions of this newsletter was a barely disguised letter of appreciation about David Roodman, a senior adviser at the Open Philanthropy Project with the unusual job description of compiling evidence on big, broad, important issues.
In the past, thatâs meant conducting highly rigorous reviews of the data on questions like âDo alcohol taxes save lives?â or âDoes releasing people from prison increase crime?â â up to and including breaking down the component studies of those reviews to see if their methodology holds up to scrutiny.
Roodmanâs latest project is even bigger: Heâs just released a new draft paper with the title âModeling the Human Trajectory.â The very modest goal is to model how human economies have evolved since 10,000 BCE. You know, easy stuff.
Debate on social scientific questions is never âsettled,â but Roodmanâs past papers were useful because they came to relatively assured conclusions that it would take considerable subsequent research to overturn.
Reading his paper on the âhuman trajectory,â I came away with the belief that ⌠human history is a beautiful mystery that we are only just beginning to unravel.
Roodman first tries to see, descriptively, how the growth rate of the world economy has evolved from 10,000 BCE to the present. He finds that itâs best represented by a power law distribution: that is, the economy hasnât grown at a steady rate, accumulating to an exponential growth explosion, but instead the rate at which the world economy has grown has itself increased as the economy has gotten bigger.
If we follow this trajectory, that implies infinite or near-infinite growth over the next few thousand years. These are the kinds of projections that led environmentally minded economists and âsystems thinkersâ in the 1960s and â70s to project some kind of bust; you canât have infinite growth on a finite planet, as the slogan goes.
Those projections havenât come to fruition yet, but that doesnât mean the intuition is wrong, Roodman argues, asking: âWhat should we make of the fact that good models of the past project an impossible future?â
One possibility he explores is that this future is not in fact impossible. If, as the endogenous growth theory of economists like Paul Romer and Charles Jones has suggested in recent decades, technology, not raw materials, is the main driver of economic growth in the long run, maybe there isnât a limit. âTechnologyâ is just a term of art we use for human ideas and inventiveness, which doesnât obey the restrictions of scarcity that apply to coal or rare-earth metals.
I am condensing a really dense and fascinating blog post about an even denser and more fascinating white paper that I absolutely do not have the math skills to fully grok, so forgive me if some is lost in translation. But I really encourage you to dive into Roodmanâs post. He doesnât arrive at a firm prediction of the future, naturally, but instead two much more modest observations:
âFirst, if the patterns of history continue, then some sort of economic explosion will take place again, the most plausible channel being AI. It wouldnât reach infinity, but it could be big. Second, and more generally, I take the propensity for explosion as a sign of instability in the human trajectory. Gross world product, as a rough proxy for the scale of the human enterprise, might someday spike or plunge or follow complicated paths in between. The projections of explosion should be taken as indicators of the long-run tendency of the human system to diverge.â
My takeaway from the piece is arguably tautological but I think still useful: The difference between our best possible future and our worst possible future could be quite literally infinite. It could be the difference between civilization ending and the kind of abundance only dreamed of in science fiction.
That makes anything we can do to shape that long-term trajectory of humanity almost indescribably important. The hard part is finding out what, if anything, can reliably make that trajectory better.
From Voxâs Future Perfect newsletter: