Chang was a law clerk for Judge Ruth Bader Ginsburg on the United States Court of Appeals for the District of Columbia Circuit from 1988 to 1989.
Prior to joining the faculty at the University of Pennsylvania Law School, Chang was a professor at the University of Southern California Law School. He has also taught law as a visiting professor at Georgetown University, Stanford University, Harvard University, New York University, the University of Michigan, and the University of Chicago.
Chang writes on a wide variety of subjects, including immigration law, international trade regulation, and environmental law. His work includes publications in the Yale Law Journal, the Journal of Political Economy, the RAND Journal of Economics, the University of Pennsylvania Law Review, the Southern California Law Review, the Georgetown Law Journal, the Journal of Legal Studies, and the International Review of Law and Economics.
Chang served on the board of directors of the American Civil Liberties Union of Southern California from 1995 to 1998 and on the board of directors of the American Law and Economics Association from 2004 to 2007.