I will also add that I'm not always convinced that a B being in the middle of the class is because of grade inflation. If the kids are put in a classroom of high-achieving kids, you would expect kids to be working hard. (In other words, I wouldn't expect to see Ds or Fs in an AP Spanish Lit class or an AP Calc BC because the kids never had to be there at all.) Since our school system has grades standardized across schools (and there are probably more than 30,000 kids in high schools), you see higher grades at the schools in the fancier zip codes.