(bigstock)

Planet Money’s blog tips us off to a fun Lapham’s Quarterly story about “Methuselah” trusts. Think of them as ultimate, get-rich really, really, really slowly scheme: trust funds set up to mature over the course of centuries, with the directive to be invested at compound interest. Compound interest isn’t usually an aggressive investing strategy; it amounts to a pretty small, annual increase on the principal investment. But since the small increase grows exponentially every year, it can become a very big sum centuries down the line. That makes a Methuselah trust “a ticking time-bomb of compounding interest — a very, very slowly ticking time bomb,” Lapham’s Quarterly’s Paul Collins writes.

The trusts have shown up throughout history; most notably, Ben Franklin set one up for Boston and Philadelphia. But the most ominous Methuselah trust is held by Hartwick College, a sleepy liberal arts school in the Catskills. In 1967, John Holden endowed Hartwick College with a Methuselah trust that would mature in 2936. Economists balked: if the trust were allowed to come to fruition, the trust would “absolutely own the world” one argued in a 1977 court case over the suit. The trust survived the suit, as well as many other challenges, and still stands today.

Methuselah trusts have, however, one major Achilles’ heel: people today aren’t so interested in accruing unimaginable wealth centuries down the line. That’s essentially what Hartwick College decided. “Hartwick College got its thousand-year trust, still bearing its maturation date of 2936; the principal now stands at an impressive $9 million,” Collins writes. “Rather than accumulating and compounding, though, the trust pays out roughly $450,000 a year to the college,” which is used to pay for things like water bills and groundskeeping.

Call Hartwick College’s decision short-sighted, practical or an averted crisis (or, some combination of the three), but it’s probably a pretty decent sign that humans with double-digit life spans aren’t going to be great stewards of trusts with quadruple-digit timelines.