Cass Sunstein

Cass Sunstein (born 1954 in Salem, Massachusetts) is an American legal scholar known for his work on constitutional law, administrative law, environmental law and behavioral economics. His influence reaches well beyond the courts: his ideas have shaped public debate about how rules and policies should be designed.

He studied at Harvard, graduating from Harvard College in 1975 and from Harvard Law School in 1978. He then clerked for Justice Benjamin Kaplan of the Massachusetts Supreme Judicial Court and for Justice Thurgood Marshall of the U.S. Supreme Court. From 1981 he taught for nearly three decades at the University of Chicago, and in 2008 he joined the Harvard Law School faculty. From 2009 to 2012 he headed the White House Office of Information and Regulatory Affairs under President Barack Obama.

His work returns to a recurring argument: constitutional law is not neutral but tends to favour the status quo, and every right, including so-called negative rights, carries a cost that the state must manage. He developed this line in The Partial Constitution and, with Stephen Holmes, in The Cost of Rights. His writing is accessible and remarkably prolific, aimed at lawyers and general readers alike.

In The Second Bill of Rights he revisited Franklin D. Roosevelt's push to extend rights to economic and social security, arguing that this agenda could win support across political divides. In Nudge, written with economist Richard Thaler, he applied decision psychology to public policy, proposing to shape the choices people face without banning anything. The idea won favour with some politicians and also drew criticism over its evidence base.

His legacy lies in applying behavioural economics to law and in rethinking how the regulatory state works. In 2014, a study of legal publications found him to be the most frequently cited American legal scholar by a wide margin.