Assessing the Relative Importance of Inputs to a Production Function

Since the publication of Michael Lewis's book, Moneyball, there has been a commonly held belief that getting on-base percentage (OBP) is more important in run production than hitting for power slugging percentage (SLG). Implicit in that conclusion is an assumption that OBP and SLG are drawn from similar distributions. The author finds, however, that they are drawn from meaningfully different distributions. Controlling for those differences, the author finds no evidence that OBP is more important in run production than SLG. In fact, the author finds that from 1980 to 2007 SLG was more important in run production than OBP.