How Many Careers?

Appropriate for post labor day. How many careers does the average person have in a lifetime? Seven is often mentioned, and I have used that approximation in an HR model. But what evidence exists for this number? In the Numbers Guy in the WSJ this number, background and evidence for its value are examined. When you are building a model of the real world it is good to be skeptical about commonly accepted numerical values. The Web is another example, from which you can scrape lots of numbers. It is good to be careful about their credibiity in the context that you use them.