Regression-Discontinuity Analysis: An Alternative to the Ex-Post Facto Experiment

Abstract

This paper has three purposes: first, it presents an alternative mode of analysis, called regression-discontinuity analysis, which we believe can be more confidently interpreted than the ex post facto design; second, it compares the results obtained when both modes of analysis are applied to the same data; and, third, it qualifies interpretations of the ex-post facto study recently reported in this journal (Thistlethwaite, 1959). Two groups of near-winners in a national scholarship competition were matched on several background variables in the previous study in order to study the motivational effect of public recognition. The results suggested that such recognition tends to increase the favorableness of attitudes toward intellectualism, the number of students planning to seek the MD or PhD degree, the number planning to become college teachers or scientific researchers, and the number who succeed in obtaining scholarships from other scholarship granting agencies. The regression-discontinuity analysis to be presented here confirms the effects upon success in winning scholarships from other donors but negates the inference of effects upon attitudes and is equivocal regarding career plans.