A labor economist friend who studies the minimum wage writes:
I found a 103 year old BLS report on a minimum wage increase in Oregon that had a stronger grasp on credible research design than Card & Krueger. Also, one of the authors is named "Bertha von der Nienburg" and she was 24 when the report was written. If I was the sort of person who did that sort of thing, I'd blog about this.
The authors are Marie L. Obenauer and Bertha von der Nienburg.
I got a little bogged down working my way through it and the authors don't come to any strong conclusions. But the care they take and the granularity of their data are amazing.
One of the things they did, besides getting data from many firms affected by the newly implemented minimum wage law, was interview some of the women affected. Here's an interesting segment from their page 68:
The belief was very prevalent among store women that the minimum wage had wrought only harm to them as a whole. The experienced women contended that formerly they had gotten through the day without any hurry or strain. If it was necessary to work a few minutes overtime, they did so willingly. Now, they said, they are under constant pressure from their supervisors to work harder; they are told the sales of their departments must increase to make up for the extra amount the firm must pay in wages. With business declining, this was hardly a possibility. The result was that the women were very worried and the worry was intensified in November, 1914--the month they were visited--because of the fear that large numbers would be dismissed after the Christmas rush was over and the dull days of January confronted the employers. These women did not ask themselves to what extent the same conditions would have prevailed in a poor business year had there been no wage regulation. They knew there were wage and hour regulations and that some women had been benefited, but if they had not personally benefited and had only experienced the pressure from above and the fear of the future, their anxiety found vent in heated denunciation of the minimum wage as the visible cause of their jeopardy.