Lifted from comments by Fred C. Dobbs at Economist View:
Supersize My Wage http://nyti.ms/1cOvtvS
NYT Magazine – December 17, 2013 – ANNIE LOWREY
About 20 years ago, in the midst of a recession, New Jersey decided to boost its minimum wage to $5.05 an hour from $4.25. Its neighbor to the west, Pennsylvania, chose not to tinker with its wage floor. Two bright young economists at Princeton, David Card and Alan B. Krueger, recognized in that dull occurrence a promising natural experiment (*).
The two found fast-food joints along the New Jersey-Pennsylvania border, and surveyed them twice over the course of 11 months about how many people they employed. They figured that when New Jersey’s minimum wage went up, Garden State burger joints would hire fewer workers. The ones on the Pennsylvania side, acting as a kind of control, would see no change.