Click on the cartoon to see a larger version.

You can also read this cartoon on the Dollars and Sense website, where they have an accompanying short article by Jason Son about how inflation tends to wipe out the gains of the minimum wage, because it’s not indexed to inflation. They also have more good articles on the minimum wage here and here. Please do click through — I think they feel paying me for my cartoons is more worthwhile if they get some traffic. :-)
This Crooked Timber post about the minimum wage by Kathy (who usually blogs at “The G Spot,” which is an excellent blog) pretty much explains the state of research on the effects of the minimum wage:
In response, Krueger and Card did another study that looked at the impact of that same minimum wage increase on employment in fast food establishments in New Jersey. To counter the previous criticisms from economists like Kevin Murphy who said that their data was problematic and that they’d got the timing wrong, this time they used a more reliable data source (employer data from the Bureau of Labor Statistics) and looked at the data over a longer time period. And guess what? This new analysis confirmed their original findings: the increase in the minimum wage did not lead to a decrease in employment.
There are a number of other reliable scholarly studies on the minimum wage that report similar results—such as this one, this one, this one, this one, and this one, for example. There are also quite a few very good studies that show the opposite—that an increase in the minimum wage does indeed bring about a decrease in employment. A fair characterization of the literature is that the minimum wage’s impact on employment is ambiguous. But the fact that the findings are mixed is fairly compelling evidence that there must be something wrong with the standard perfect competition model of employment. […]
Krueger and Card have written a paper that provides strong evidence that “specification searching and publication bias” have led to an overrepresentation of studies that find that the minimum wage has a statistically significant disemployment effect. The ideological character of much of the economics profession in the United States suggests that there are rewards for producing scholarship that confirms the idea that the minimum wage causes unemployment, and punishment for scholarship that finds otherwise.
It’s worth mentioning that even those peer-reviewed studies that find negative effects of the minimum wage, usually find very small effects.