An economist imagined dropping cash from a helicopter to explain inflation

In a 1969 essay, Milton Friedman used a thought experiment, a helicopter dropping $1,000 in cash on a community, to explain how a pure increase in the money supply, with nothing else changing, drives prices up rather than making anyone genuinely richer. The phrase 'helicopter money' has since become shorthand for any policy of injecting cash directly into an economy.

— Milton Friedman, The Optimum Quantity of Money — essay collection, 1969