As the baby boom generation of teachers retires, schools are facing shortages of qualified teachers:
"It's not that you don't have some terrifically talented people going into teaching. You do," said Richard J. Murnane, an economist at Harvard University's Graduate School of Education. "The issue is that you don't have enough. And many are the most likely to leave teaching, because they have lots of other opportunities."...
To offset a shortfall of 280,000 qualified math and science teachers projected by 2015, the National Council of Teachers of Mathematics advocates more competitive pay -- a controversial move away from a fixed salary structure that some teacher advocates say reflects a mentality that teaching is a second income.
Only in government-run schools can people believe that paying someone on the bases of aptitude and performance is "controversial."