It's been around for a long time. Freakonomics did a podcast on it in 2010 (http://freakonomics.com/podcast/freakonomics-radio-how-much-...).

In my view, the extent to which the President can be credited or blamed for job numbers is a topic that is discussed periodically in the press.

For fun, I just googled "don't blame president ford for unemployment" and there were several hits.