Looking at it from the outside, I would say that teaching one set of models the first years and then showing the more advanced ones that show the faults of the first year's models serves multiple purposes.

1. You can indoctrinate a large number to serve as loyal footsoldiers - bureacrats in companies in the case of economics - while
   
2. educating those that show talent for the subject further to keep some a second line of intellectual defense.

A vote for PES is a vote for EPP! A vote for EPP is a vote for PES! Support the coalition, vote EPP-PES in 2009!