Competitive Balance in Major League Baseball

With the MLB's regular season in the books, I want to look at MLB over the next four days with regard to:  competitive balance, payroll inequality, payroll and performance and attendance analysis. To begin, I examine competitive balance in MLB using the regular season standings and the Noll-Scully measure of competitive balance.  For those not familiar with this measure, start here.  For those interested in calculating this on your own, try this step-by-step measure.  For the calculations below, I am using data from Yahoo! Sports:  https://sports.yahoo.com/mlb/standings/

First, let's start with the most recent MLB regular season:  2018.  The Noll-Scully measure of competitive balance for the American League was: 2.793 and for the National League was:  1.579.  Clearly, the National League was much more competitive this season than the American League.  For MLB in total, the Noll-Scully was:  2.263.  While this is indicative that MLB was not extremely competitive, is the 2018 regular season typical, more competitive or less competitive?  To answer that, I calculate competitive balance since 2002 and display it on a graph below.



As you can see, for the National League, it is similar to previous seasons in terms of competitive balance, but for the American League, it is not.