I can't find the exact reference but I believe somewhere in the book they talk about the mere fact of entering your student into this lottery to go to a better school meant that the student would have better outcomes (regardless of whether they "won" the lottery or not).
The idea being that it was the mere "intent" of a parent wanting better for their child that had the most impact on student performance.
http://www.freakonomics.com/2007/10/04/more-evidence-on-the-...
I can't find the exact reference but I believe somewhere in the book they talk about the mere fact of entering your student into this lottery to go to a better school meant that the student would have better outcomes (regardless of whether they "won" the lottery or not).
The idea being that it was the mere "intent" of a parent wanting better for their child that had the most impact on student performance.