Predominance & Rigorous Analysis - Parko v. Shell Oil Co.

Judge Richard Posner has always been an independent thinker, something he has proven in the last year as, despite his economically conservative credentials (which would lead one to presume a possible defense bias), he authored a number of arguably pro-plaintiff class certification opinions, particularly his twin opinions in the controversial case Butler v. Sears Roebuck & Co. (2012) (2013) And so it is noteworthy that, despite his ruling in Sears, he has also authored the opinion in Parko v. Shell Oil Co., No. 13-8023, 2014 U.S. App. LEXIS 1018 (7th Cir. Jan. 17, 2014).

Parko involves an environmental class action filed by property owners in Roxana, Illinois against several oil companies that allegedly ran a refinery that leaked benzene into the surrounding groundwater. The plaintiffs sought damages for the reduction in their property values. The district court certified the class, and the defendants appealed, arguing that it had not found that the common question