It is commonly claimed in the recent happiness literature in psychology and economics that we have proved diminishing marginal utility of income. This paper suggests that we have not. It draws a distinction between concavity of the utility function and concavity of the reporting function. --...

I suggest the idea of a reporting function, r(.), from reality to feelings. The 'happiness' literature claims we have demonstrated diminishing marginal utility of income. I show not, and that knowing r(.)'s curvature is crucial. A quasi-experiment on heights is studied. -- Money ; diminishing...