Transaction costs (TC) are the "friction" in an economic system, and their analysis is vital to understanding institutional design and economic performance. Law and Transaction Costs in the Ancient Economy is the first volume to collect specific studies from a transaction cost perspective. The volume offers models of this new way of looking at ancient evidence, and suggests ways in which traditional subject areas might inform problems in contemporary economics and legal studies. After the editors' methodological introduction, the contributors investigate the roles and effects of transaction costs in fourth-century Athens, Ptolemaic Egypt, the Roman Empire, and late antiquity, on the basis of legal texts, papyri, and inscriptions. Collected here are some of the leading voices on TC analysis in ancient history, as well as established scholars, including several who do not usually publish in English: Alain Bresson, Giuseppe Dari-Mattiacci, Rudolf Haensch, Dennis Kehoe, François Lerouxel, J. G. Manning, Brian Muhs, Josiah Ober, David M. Ratzan, Gerhard Thür, and Uri Yiftach. This volume will speak to those who identify with traditional subject areas, like epigraphy or Greek law, and will also demonstrate the value of experimenting with this new way of looking at ancient evidence.