Happiness and utilitarianism

A recent cross-blog thread about what happiness means:

1. Will Wilkinson: responding to some erroneous statements in Richard Layard's recent philosophy book Happiness.
2. Brad DeLong replies, defending the notion of happiness-maximization.
3. Will Wilkinson rejoins, dissecting the concept of "happiness" as it is normally understood.
4. Julian Sanchez weighs in, noting that certain abstract philosophical notions of happiness don't map very well onto actual human psychology.
5. Brad DeLong comments, without much explanation, that he finds the objections to happiness-maximization unconvincing.

Of course, longtime readers (all three of you) know that the theory of happiness is a longstanding concern on this blog, and I come down roughly on the side of Wilkinson and Sanchez --- one, two, three, four.