There is little good empirical evidence about the minimum wage, period. I'd have a hard time showing any harm, and you'll have a hard time showing any benefit.
That's because the minimum wage is usually set at such a low level that it applies to very few workers (<1.5M in the US, as of 2007), so very few natural experiments are available.
I'll give you one natural experiment, however. A min wage hike in American Samoa caused unemployment to increase by at least 6% (= 2041 workers fired by Chicken of the Sea / (65k American Samoans x 52% labor force participation rate)).
That's because the minimum wage is usually set at such a low level that it applies to very few workers (<1.5M in the US, as of 2007), so very few natural experiments are available.
http://www.bls.gov/cps/minwage2007.htm
I'll give you one natural experiment, however. A min wage hike in American Samoa caused unemployment to increase by at least 6% (= 2041 workers fired by Chicken of the Sea / (65k American Samoans x 52% labor force participation rate)).
http://washingtonexaminer.com/node/127791