What a difference a few decades make. In 1970, just over 14 percent of bachelor's degree recipients majored in business. In 2010, it was 22 percent. Looking at plain numbers, the change is even starker: 115,000 in 1970, and over 360,000 in 2010. Why do we now have triple the number of graduates with business degrees, and which areas of study have declined as that major surged?