Matrixx v. Siracusano and Student v. Fisher

Statistical significance on trial


  • Stephen T. Ziliak

    1. Trustee and Professor of Economics at Roosevelt University, Chicago, and has published extensively on statistical significance and practical importance.
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  • He is the author, with Deirdre McCloskey, of The Cult of Statistical Significance: How the Standard Error Costs Us Jobs, Justice, and Lives (University of Michigan Press, 2008).


“Matrixx's argument rests on the premise that statistical significance is the only reliable indication of causation. This premise is flawed.” So ruled the US Supreme Court this year in a judgment of huge significance. As a drug company learns that it must disclose even statistically insignificant side effects, Stephen T. Ziliak congratulates the judges, and two giants of statistics fight on from their graves.