The math and science gap.
Jack Shedd and an interesting post on his blog at www.bigconstrain.com.
He quoted Philip Greenspun saying:
“[A school administrator] explained that school teacher salaries are set by unions and governments so that teachers of all subjects get paid the same. The current salary is much more than necessary to attract qualified social studies teachers. At current salaries, she could find qualified replacements for all of the non-math/science teachers in her school system within a week or two. People who understand math and science, however, find the current package of salary and working conditions unattractive and find work elsewhere…”
He goes on to point out that “A lack of math and science teachers creates a gap between the availability of folks with a strong interest and aptitude for the subject and its demand. As the divide widens, those individuals can command higher and higher salaries, meaning fewer and fewer will accept teaching positions.”