Economic thought in the 20th Century

A question from Yahoo! Answers:

Economic Schools in the 20th Century?

I’m writing a paper comparing the various schools of economic thought that were prevelant in the 20th century. My goal is to discuss the most influential and important schools as well as cover a wide spectrum of thought. I need to compare at least four schools, but at most five, so which schools do you think should be included?

1. The neoclassical school
2. Keynesian economics
3. Rational-expectations economics
4. Non-structural econometrics

And, if you have any room left, the dynamic stochastic general equilibrium economics.