modern · 1910 to 2013

Ronald Coase: The accountant of friction

Economics assumed that trading was free. Coase asked what it costs to find a partner, strike a bargain, and enforce it, and found that the answer explains why firms exist and who ends up owning what.

Facts reviewed 2026-09-09.

Ronald Coase was a British economist who spent most of his career at the University of Chicago Law School, where he edited the Journal of Law and Economics and helped turn the study of legal rules into an economic discipline. He wrote very few papers and two of them reorganized a field.

The first, written when he was in his twenties, asked a question the textbooks had not thought to ask: if markets allocate resources efficiently, why is so much of the economy organized inside firms, where orders replace prices? The second asked who should bear the cost when one party's activity harms another.

Coase's answer to both questions was the same: using a market is not free. Finding the right counterparty, learning what a thing is worth, negotiating terms, and enforcing the deal all consume real resources. He called these transaction costs, and once they are on the ledger, the boundary of a firm stops being a mystery. A firm grows until organizing one more activity internally costs more than buying it outside.