That is David Neumark in the WSJ, here is one excerpt:

Another recent study by Shanshan Liu and Thomas Hyclak of Lehigh University, and Krishna Regmi of Georgia College & State University most directly mimics the Dube et al. approach. But crucially it only uses as control areas parts of states that are classified by the Bureau of Economic Analysis as subject to the same economic shocks as the areas where minimum wages have increased. The resulting estimates point to job loss for the least-skilled workers studied, as do a number of other recent studies that address the Dube et al. criticisms.

The piece is a good brief survey of some of the developments since Card and Krueger. Here are some alternate links to the piece.