Policy Evaluation

Policy evaluation is the systematic assessment of the design, implementation, outcomes, and costs of public policies and programs in order to judge whether they achieve their goals and what effects they have on different groups. It uses experimental and quasi-experimental designs, cost-benefit analysis, process studies, and qualitative methods. Donald Campbell championed the experimenting society and set out principles of quasi-experimental design, while Carol Weiss argued that evaluation should be understood within the political context in which decisions are made and used. Peter Rossi, Howard Freeman, and Mark Lipsey produced a standard account of program evaluation, and Ray Pawson and Nick Tilley developed realist evaluation, asking what works for whom in which circumstances. Egon Guba and Yvonna Lincoln proposed constructivist fourth-generation evaluation, emphasizing stakeholder perspectives. Esther Duflo and Abhijit Banerjee popularized randomized controlled trials in development, while critics such as Angus Deaton and Nancy Cartwright question their generalizability. Michael Lipsky showed that implementation at street level shapes outcomes, and Deborah Stone highlighted the political construction of success. Evidence-based policy movements raise concerns about technocracy and neglected values. Policy evaluation remains central to research on welfare, education, health, governance, and public accountability.