Traditionally employees would work for only a few companies. If you could ideally get a job with IBM right after college, you would stay there for the rest of your life until you retired. This is not the case anymore. The job market is much more fluid inflexible. Not only our employees more likely to leave, but employers are more likely to refocus their efforts, shift employees around, they vest themselves of certain business units, and downsize when the economy slows.
These changes are creating a very different type of work force. It’s not uncommon for someone to work a dozen of different places before they retire. This trend appears to only be accelerating and it looks like it will be, and for the upcoming generations to only work somewhere wanted three years before switching to a different job.