Sapiens: A Brief History of Humankind

by Yuval Noah Harari

worthwhile investment. He issues her a $1 million loan, by crediting her account in the bank with that sum. McDoughnut now hires Stone, the contractor, to build and furnish her bakery. His price is $1,000,000. When she pays him, with a cheque drawn on her account, Stone deposits it in his account in the Greedy bank. So how much money does Stone have in his bank account? Right, $2 million. How much money, cash, is actually located in the bank’s safe? Yes, $1 million. It doesn’t stop there. As contractors are wont to do, two months into the job Stone informs McDoughnut that, due to unforeseen problems and expenses, the bill for constructing the bakery will actually be $2 million. Mrs McDoughnut is not pleased, but she can hardly stop the job in the middle. So she pays another visit to the bank, convinces Mr Greedy to give her an additional loan, and he puts another $1 million in her account. She transfers the money to the contractor’s account. How much money does Stone have in his account now? He’s got $3 million. But how much money is actually sitting in the bank? Still just $1 million. In fact, the same $1 million that’s been in the bank all along. Current US banking law permits the bank to repeat this exercise seven more times. The contractor would eventually have $10 million in his account, even though the bank still has but $1 million in its vaults. Banks are allowed to loan $10 for every dollar they actually possess, which means that 90 per cent of all the money in our...