And this thought from Will Wilkinson
My hunch is that these folks aren’t really utilitarians after all. They have a prior intuition about the injustice of inequality, and the justice of progressive redistribution. Then, they attempt to undermine resistance to higher tax rates on the wealthy by pointing to research that they interpret to say that this won’t make the wealthy any less happy, and so, Why worry? The trouble is, it won’t make the poor (in a country like the US where the poor are already rich) much happier either, and won’t do anything to change relative position in the distribution. So what’s the point? The point is more progressive redistribution, to which many folks are committed to prior to and independent of utilitarianism or their interest in happiness.