You're not wrong in principle that you could have a utility function with positive expected value for playing the lottery, but that's misleading. Generally it

You're not wrong in principle that you could have a utility function with positive expected value for playing the lottery, but that's misleading. Generally it is taken that money has diminishing marginal utility. This is even more salient for poor people, for whom the marginal value of $1 at their current wealth is vastly more than the value of $1 at the wealth of winning the lottery; i.e. playing the lottery is even worse, in terms of expected value, when you apply a reasonable utility function. You're correct about your mafia example, but that's highly contrived. I contest that your second example does not show what you claim; that is exactly the sort of person who should not be playing the lottery.