Diminishing marginal utility? Well, it's not like billionaires spend most of their money on personal consumption. Many ways of spending money also generate util

Diminishing marginal utility? Well, it's not like billionaires spend most of their money on personal consumption. Many ways of spending money also generate utility for others. The real choice is whether to let the billionaire keep the marginal million dollars (which he might choose to invest or donate to charity), or give that million to the government to do as it sees fit (e.g. distribute it among poor people). Which choice yields greater expected total utility? Are there any numbers on that?