Sorry I didn’t see this earlier. I wasn’t endorsing rule utilitarianism; I was only saying that Anton’s point sounded a lot like rule utilitarianism, and that if we accept that rule utilitarianism is the correct way to evaluate different institutional structures, it wouldn’t be necessarily true, or even clearly conventionally true, that libertarian conceptions of property rights satisfy the criteria necessary for endorsement.
To answer your question, though, I think that behind the veil of ignorance people wouldn’t endorse either principle. A maximin principle implies that people are perfectly risk-averse expected welfare maximizers, and nothing else. A rule utilitarian view is similar, but with perfectly risk-indifferent maximizers. I like the veil of ignorance as a tool for thinking about different kinds of social orders, but I don’t think that matters of welfare would be the only thing that would matter to people behind the veil. When I think of the kind of society I would want to live in, I certainly think about what kinds of lives people will be able to live, but I also think about matters more closely tied to justice: Will people be protected in their entitlements? Will people generally deserve what they get, and will opportunities go to those who deserve them? Will people be treated with respect and deference to their individuality and dignity? Will norms of reciprocity and goodwill be fostered? Will those in need be provided for in a way that reflects their importance and worth as individuals, but is also respectful of the individuality of those who will be supporting them? Will the society progress in a way that gradually reduces the frequency of instances of serious need? Will people feel connected to others in their communities so that mutual assistance and cooperation will flourish?
These sorts of things seem fundamentally important to evaluating a society, and don’t seem to be directly captured in the idea of welfare maximization. Of course, consequentialists would likely disagree, claiming that either these matters are only instrumentally important, or that it is irrational to value them for themselves. But I think that the mark of a good society is that it embodies both an attitude of respect for individuals and the fact their lives are the only ones they have, and also the idea that we all share our common humanity, and that should be celebrated and cherished. I think that both rule utilitarianism and maximin views are better at the second part, and not quite as good at the first part. A more complete approach to institutional evaluation, I think, would take into account both consequences and justice.