The Infinity Fallacy

You’ve probably heard of short-termism, a mode of thinking where one lives like each day is their last, to predictable consequences. I am looking to label its extreme opposite—accumulation which fails to have an adequate (or any) spending phase.

Some examples:

  • Strategy/​card game players often play “too greedy”. New slay the spire players may avoid wraith form or dead branch because these effects come with infinitely ramping downsides.

  • The EA pledge pushes us to give 10% even early in our careers, presumably in part to undermine our tendency to accumulate, accumulate, then die of old age.

  • One reason to oppose resource extraction is that it is irreversible. Once you take the oil and burn it, we permanently have less oil, and what if we need it in 10000 years?

  • Taxation—in a framework where low taxes bolster growth and pay for themselves with a bigger tax base, the policymaker still has to ask “when?”. If I am only interested in maximizing tax take, halving the tax rate to double the tax base is great if it happens in a year, less so if it takes a century.

One is committing the Infinity Fallacy if, given a choice between a short- and a long-term action, they always pick the long-term without considering if the payoff will actually materialize within their lifetime/​planning horizon.

I use the word “infinity” here because I think that the most egregious errors of this type happen when we treat the opportunity cost or compound gain of an action as something that will follow us forever. “If you save $1 today, next year it will give you $0.07, which will earn you even more and so forth until eventually it turns into untold riches and infinite utilons.”

When committing the Infinity Fallacy, the long-term choice can always mug you by promising to provide infinite utils. Instead, we should calculate with a finite term—“I expect this $1 to compound over X years and ignore growth afterward because I will be dead/​scammed/​AI will make money useless.”