When Value Judgments Masquerade as Science

By the Kaldor-Hicks criterion, a public policy is judged to enhance economic efficiency and overall social welfare — and therefore is to be recommended by economists to decision-makers — if those who gain from the policy could potentially bribe those who lose from it into accepting it and still be better off (Kaldor), or those who lose from it were unable to bribe the gainers into forgoing the policy (Hicks). That the bribe was not paid merely underscores the point.
That is quite a mouthful. As the economist Steven E. Landsburg explains it bluntly to students in “Price Theory and Applications” :

In applications, the Kaldor-Hicks criterion and the efficiency criterion amount to the same thing. When Jack gains $10 and Jill loses $5, social gains increase by $5, so the policy is a good one. When Jack gains $10 and Jill loses $15, there is a deadweight loss of $5, so the policy is bad.

Evidently, on the Kaldor-Hicks criterion one need not know who Jack and Jill are, nor anything about their economic circumstances. Furthermore, a truly stunning implication of the criterion is that if a public policy takes $X away from one citizen and gives it to another, and nothing else changes, then such a policy is welfare neutral. Would any non-economist buy that proposition?

Full blog post here 

And Landsburg's response :

For economists evaluating alternative policies, the industry standard is the efficiency criterion, also known as the welfare criterion. (I’ll illustrate what that means as I go along.) But now comes Princeton Professor Uwe Reinhardt with a piece in the New York Times that questions the orthodox approach found in virtually all modern textbooks (including one in particular).
Let’s first dispense with the straw man. I’ve never heard of an economist who believes that every efficient policy is good, and I’ve heard of very few who believe that every inefficient policy is bad. It’s true that most economists do seem to believe that any good policy analysis should start by considering efficiency. That doesn’t mean it should end there.

I think economists are right to emphasize efficiency, and I think so for (at least) two reasons. First, emphasizing efficiency forces us to concentrate on the most important problems. Second, emphasizing efficiency forces us to be honest about our goals.