Notice that I did not say "all studies"? Thanks for those 6 examples. Here's a lot more of them over the past 50 years:

http://www.jec.senate.gov/public/_cache/files/c876c468-ffca-47ed-9468-7193d734bde9/50-years-of-research-on-the-minimum-wage---february-15-1995.pdf

While it is not yet clear why Card, Katz and Krueger got the results that they did, it is clear that their findings are directly contrary to virtually every empirical study ever done on the minimum wage. These studies were exhaustively surveyed by the Minimum Wage Study Commission, which concluded that a 10% increase in the minimum wage reduced teenage employment by 1% to 3%.