Your personal attacks here are pathetic and boring. How embarrassing it must be for you to be corrected on economics by a philosopher who knows next to nothing on the subject. But here we are.
As Chang point out, the disagreement between pareto optimality and utilitarianism is philosophical. Regardless of what economists state explicitly in using pareto optimality, they presuppose a philosophical stance on values by denying the relevance or the appropriateness of the utilitarian counterexample, in which a minority is harmed/sacrificed to benefit the majority, according to a higher sense of fairness/justice/goodness.
I'm not imposing a normative interpretation. I'm agreeing with Chang that there's a philosophical, normative dispute between pareto optimality and utilitarian conceptions of what's economically best. Scientistic, bureaucracy-minded economists like you hide this disagreement by pretending that "Pareto optimal does not tell us what one person deserves or does not deserve." Alas, just because you're not upfront about your value judgments doesn't mean you're not implicitly making or presupposing any.
If pareto optimality entails that the Robin Hood scenario is suboptimal or forbidden, then yeah, that "optimality" is based on the Sheriff of Nottingham's sense of morality.
Pareto optimality presumes you shouldn't make people "worse off," since the optimal situation is supposed to be the one in which the only way to further improve one person's status would be to harm someone else. Pareto optimality is reached without harming anyone or taking from someone without that person's consent. As the article below says, "a Pareto improvement is a new situation where some agents will gain, and no agents will lose." Thus, "A situation is called Pareto-optimal or Pareto-efficient if no change could lead to improved satisfaction for some agent without some other agent losing or, equivalently, if there is no scope for further Pareto improvement." That is, the situation is optimal without the losses to some agents. Thus, those losses are excluded from pareto optimality.
But the question pareto optimality elides is whether some "harms" are justified on moral or some other higher grounds that scientistic economists prefer not to contemplate. That's part of the dispute between classical and neoclassical economics which hasn't been resolved because it's philosophical rather than scientific, and because your type of economist wants to sweep it under the rug. Pareto's exclusion of sacrificial or utilitarian "harms" for the greater good is the philosophical, normative issue I'm uncovering here rather than imposing.
