Yeah I'm sorry but I'm going to put more stock in basic math and logic than I put in a 9 month study of two states. If prices aren't allowed to do the job of distributing labor resources efficiently, a cost is paid by everyone for that sooner or later, all things being equal. Empirical data is tricky where this is concerned because all things are rarely equal. It could easily have been that the New Jersey economy was in a better situation than the Pennsylvania one. Penn could have had a different state government with different economic policy (aside from the minimum wage).

If there is now someone who would have agreed to a lower wage who can no longer agree to that wage, the economy has lost some amount of value. Sometimes it works to that person's favor and he gets paid the minimum wage, sometimes it doesn't, but on the whole we all lose. It becomes ever-so-slightly more difficult and risky to start or expand a business, and ever-so-slightly more difficult for low-skill workers to find work.

The Keynesian logic of low income consumers "spending the money back into the economy" is a complete joke. Money at the top gets utilized as well, often in much more productive ways. It gets invested and loaned out, resulting in lower natural interest rates*. It's much more likely to contribute to GDP growth and innovation, and much more likely to result in lower prices of goods and services in the economy.

*This doesn't particularly matter as much with the way things are because of central banking, which controls the interest rate. But central banking is destroying the world economically and creates business cycles. Ask Greece, Spain, Italy, and Portugal how this is working out for them.