In another reading today, I came across a quote attributed to a congressman as he was speaking to his colleagues... He was talking to them about a policy decision or a program that they were considering and he said, "Don't pretend that you know what you don't know..."  This is attributed to Senator Moynihan and he was urging congress not to pass something with no knowledge of the theory that drove the idea or testing the theory itself.  
(I read this in a book chapter written by Eleanor Chelimsky.)

I want to think about that statement because it is very important.  I will think about it(out loud to you) in regards to the theory/idea that I support - that 1)providing access to information about food (calories for example) and 2)access to healthier foods (perhaps with lower pricing) will lead to informed eating and possibly a lessening of the obesity crisis that America and many countries now face.

Do I KNOW that the policies that make these strategies a reality will work?  NO.  Are the ideas based on a theory - YES.  Can this be tested?  Yes.  Has it been?  Yes - on a small scale.  Should we continue to test it when we implement it?  Yes.  Does the theory include more than just providing the information?  YES.  What else is needed?  Education and Promotion.  Should the evaluation of the policy also consider the amount of education and promotion that was delivered?  Absolutely.
What are we waiting for?  I have no idea!