Steven Landsburg suggested that those who want to tax the rich should voluntarily pay more taxes themselves. I disagreed. Tyler Cowen responds

Karl Smith is irritated by the argument, but I don’t see that he offers a good response.  In general the responses I read or hear to this argument show a lot of emotion and not a lot of recognition of the strongest versions of the claim.  Even if this argument has a chance of truth of only 20 percent, that still should have force to alter behavior at the margin.  “There is a twenty percent chance I am morally compelled to give” is a real nudge toward “I should give more now,” if only, say, giving a fifth of what the full argument requires.  So “downgrade and dismiss” — a common rhetorical strategy — won’t work here.  If the argument has any life at all, it should hang like a millstone around the neck of egalitarians.

The best response is to accept the argument and admit one’s partial moral inferiority: “The people who give more, yes, in some important ways they are better people than I am.”

I think Tyler is more or less correct here though I don’t know that we need the probabilistic language.

If you believe there is a moral duty to contribute towards helping the poor and you do not do so, then you bear moral responsibility.

My argument was less powerful than that. I suggest that a rich person can consistently favor taxes on the rich without volunteering to pay such taxes him or herself. The argument is simply that the world in which every rich person pays is preferable to me to the world in which no rich person pays which is preferable to me to the world in which only I pay.

Bryan Caplan pushes further asking under what conditions could someone suggest that there is a moral duty to tax the rich but not a moral duty for each individual rich person to volunteer taxes.

The simplest moral theory I can imagine that would justify Karl’s position says: (a) you’re morally obligated to obey the law, (b) morally obligated to support utility-maximizing laws, but (c) not morally obligated to unilaterally maximize utility.  But just imagine making a populist protest sign consistent with this position.  An egalitarian who defers to the law, does cost-benefit policy analysis, and refuses to go above and beyond the call of duty has become everything he hates.

So the obvious response – though I am not necessarily endorsing it – is that one has the following moral obligations:

A moral obligation to follow the law.

A moral obligation to advocate for laws one would have chosen in the Original Position.

A moral obligation to maximize the health and welfare of one’s family consistent with the law.

This would represent – I think -  the revealed morality of most egalitarians. Is this what they hate?