Are high school AP classes a scam?

One columnist at The Atlantic thinks so:

Interestingly, the evidence providing the clearest positive argument for AP participation is that high performance in AP courses correlates with better college grades and higher graduation rates, especially in science courses. But that's faint praise. It's the same as saying that students who do best in high school will do better in college and are more likely to graduate.

My beef with AP courses isn't novel. The program has a bountiful supply of critics, many of them in the popular press (see here and here), and many increasingly coming from academia as well (see here). The criticisms comport, in every particular, with my own experience of having taught an AP American Government and Politics course for ten years.

He goes on to argue that

• AP courses are not remotely equivalent to the college-level courses they are said to approximate.
• Increasingly, students don't receive college credit for high scores on AP courses...
• Increasing numbers of the students who take them are marginal at best...
• Large percentages of minority students are essentially left out of the AP game...
• Schools have to increase the sizes of their non-AP classes, shift strong teachers away from non-AP classes...
• The AP curriculum leads to rigid stultification.

I sent the link to two friends who have been high school principals.  Both of them disagreed with the premise.

"These were expensive to run because a teacher teaching five students sees fewer students in a day. One might make the case that this diverts resources from areas. But this does not only happen with AP courses."

"I never experienced students being encouraged to enroll in AP classes just so the class could reach an enrollment minimum."

 "(our) district went out of its way to recruit black students into the AP programs."

 "He doesn't like that many AP scores don't allow a student to earn credit, only exemption from a basic level course. My experience and opinion is that is not a big problem."

"In this day and age of whopping college costs, dual-enrollment fills for many kids a better, more intelligent slot than AP."

The arguments are fleshed out in more detail at The Atlantic and the links embedded there.