The man who arguably founded modern economic theory, the 18th-century Scottish philosopher Adam Smith, popularized the idea that barter was a precursor to money. In The Wealth of Nations, he describes an imaginary scenario in which a baker living before the invention of money wanted a butcher’s meat but had nothing the butcher wanted.“No exchange can, in this case, be made between them,” Smith wrote.
On paper, this sounds a bit like delayed barter, but it bears some significant differences. For one thing, it’s much more efficient than Smith’s idea of a barter system, since it doesn’t depend on each person simultaneously having what the other wants. It’s also not tit for tat: No one ever assigns a specific value to the meat or cake or house-building labor, meaning debts can’t be transferred.