Eric Hanushek presents the case for eliminating the lowest performing teachers. He believes that simply replacing as few as 5% of the worst teachers with only average teachers would pretty much eliminate the education gap with other high-performing countries and would result in a massive increase in our long-term economic outlook.
The key paragraph is this one:
Admittedly, these estimates are subject to some uncertainty. So if you think those that are given here are too high, even though they are based on the best of contemporary research, then just cut them in half. You will still have effects on growth of one-half of 1 percent per year, which produces impacts of $56 trillion over the lifetime of today’s child. In other words, to make the very large effects disappear, you have to make either the very strong assumption that student learning has little effect on the U.S. economy or the equally strong assumption that teachers have little impact on students.Which is it? If a good education makes a difference, then having a bad teacher also makes a difference. The teaching profession is not a magical Lake Wobegon. Not all teachers are above average.