Professor Langbein teaches quantitative methods, program evaluation, policy analysis, and public choice. Her research fields include: theories of bureaucratic discretion, productivity, principal-agent models, social capital, and cooperation in the workplace; theories of influence of interest groups in Congress and the bureaucracy; empirical applications in various policy areas, including the environment, education, defense, housing, criminal justice (death penalty and police), and corruption. Her articles have appeared in numerous journals on politics, economics, policy analysis and public adm...