The regression discontinuity model has recently become a commonly applied framework for empirical work in economics. Hahn, Todd, and Van der Klaauw (2001) provide a formal development of the identification of a treatment effect in this framework and also note the potential bias problems in its...

This paper is a revised version of a keynote address delivered at the inaugural International Industrial Organization Conference in Boston, April 2003. I argue that new econometric tools have facilitated the estimation of models with realistic theoretical underpinnings, and because of this, have...