What would happen if the world stopped using money?

As Answered on Quora

Billions of people would die.

Without a medium of exchange and unit of account, coördination of capital would become utterly incoherent, and the established interdependence of the modern age would vanish.

Most people would become useless to others, unrewardable.

And violence would reign supreme, as there would be a scramble to capture existing resources. Economists would utter the words “consumption of capital” before they were placed against the wall and shot en masse.

Mass starvation, rioting, tyranny, and death would follow, and quickly. Progress would not merely halt, regress would set in. We would go back to a stone age. A few technological utopias may survive, but the cost would be extraordinary.

For billions and billions of people would die miserable, horrifying deaths.

And the population would reduce itself to something like twice the population of bears.

In the meantime, certain infrastructure elements, like nuclear power plants, might very well fail and poison the planet . . . that is, if the malign individuals who capture the nuclear arsenal do not usher in nuclear winter, first.