The spending rule is the lesson. If an endowment earns about 7% a year on average and spends about 4%, the remaining 3% roughly keeps up with inflation, so the trust can fund schools forever. Spend 8% and it slowly eats itself. The same arithmetic applies to anyone who will one day live off savings.
Not every fund is so healthy. Hawaiʻi's Employees' Retirement System, which pays pensions to teachers, police and other public workers, held about $26 billion against far larger promises, roughly 64% funded. Closing that gap falls on future taxpayers.
Employees' Retirement System of Hawaiʻi, 2026. Compiled from secondary reporting; check the primary source.
The ahupuaʻa, a traditional land division from mountain to sea, offers another frame: a whole system in which every resource is used, shared and replenished within one community. Good financial planning thinks the same way, about the long run and about who comes after you.