A recent US federal district court ruling finding a defendant’s evidence of cost savings inadmissible could change how efficiencies evidence is presented in merger cases.

A US federal district court ruling last month has prevented Penguin Random House LLC from using certain economic data to justify its $2.18 billion acquisition of Simon & Schuster Inc. after the judge issued a midtrial order excluding Penguin Random House’s evidence of predicted cost savings — cost savings the publisher argued would be passed on to authors in the form of higher book advances.