I like the greenhouse question (page 17). I can not imagine that the authors does not know that correlation does not imply causation http://en.wikipedia.org/wik

I like the greenhouse question (page 17). I can not imagine that the authors does not know that correlation does not imply causation http://en.wikipedia.org/wiki/Correlation_does_not_imply_causation http://en.wikipedia.org/wiki/Correlation_does_not_imply_caus...