Ronald Coase was the 1991 recipient of the Nobel Memorial Prize in Economic Science "for his discovery and clarification of the significance of transaction costs and property rights for the institutional structure and functioning of the economy." The "Coase Theorem," as it later became known, challenged the rationale for government intervention in disputes over externalities. Coase was the Clifton R. Musser Professor Emeritus of Economics at the University of Chicago Law School. He was the author of numerous books, including The Firm, The Market and the Law and Essays on Economics and Economists. He was a contributor to Cato's 1999 book, What Do Economists Contribute? edited by Daniel B. Klein.