Adams, Gregory; Noether, Monica - In: International Journal of the Economics of Business 18 (2011) 1, pp. 33-40
This note explains why the difference-in-differences methodology, as applied by Deborah Haas-Wilson and Christopher Garmon in their paper "Hospital Mergers and Competitive Effects: Two Retrospective Analyses" contained in this issue, does not produce credible results when applied to an...