Is this true? It has been so long since I was close enough to it, so I can't be sure it is still this way, but I have several teachers in the family, and they used to have a choice. Collect unemployment for 2.5 months or get a summer job to supplement the income. Assumption coming -> It may be because they weren't offered the choice of 9 or 12 months. 9 is all you got.
Not that I disagree with the rest of your premise, but when said the above the way you did, it struck chord of memory.
E.g. Had an uncle that worked as high school teacher, and he worked for Ford on the assembly line for the summer, making nearly the same or more than they made as a teacher for those 3 months.
Sorry for interjecting, what I am saying may mean nothing at all to the argument, but still wanted to chime it. :*)
