Since 1994, Ayres has served as the William K. Townsend professor at the Yale Law School and is a professor at the Yale School of Management. He teaches antitrust, civil rights, commercial law, contracts, corporations, corporate finance, law and economics, property, and quantitative methods. In 2006, Ayres was elected a fellow of the American Academy of Arts and Sciences, and also currently serves as a research associate at the National Bureau of Economic Research'. Ayres has previously served as a research fellow of the American Bar Foundation and has clerked for James K. Logan of the Tenth Circuit Court of Appeals. In a post-conviction petition, Ayres was successful in vacating the death sentence for his client.