Nozick's Wilt Chamberlain example

Let's say a bunch of poor kids all pay to see Wilt Chamberlain play basketball.  Wilt gets the money, the kids get to see the game.  At the end of the day Wilt is richer and the kids are poorer.  Since we wouldn't object to any one of these transactions, why should we object to the resulting pattern?  Robert Nozick went further and argued that any "pattern-based" notion of justice would require continual and unjustified interference in personal liberties.  That was one of the most famous claims in his Anarchy, State, and Utopia; here is another summary of the argument. 

I'm all for the NBA but I've never been overwhelmed by this approach.  I agree that there is "nothing unjust" about the Chamberlain outcome but still perhaps we can do better in consequentialist terms.  Nozick's argument defeats egalitarian leveling but does it really refute, say, mildly progressive taxation?  What if we could tax Wilt a bit and make life much better for the kids?  Without invoking public choice skepticism about government (which indeed is important), what's so bad about that?  Is it morally wrong?  Wilt is still quite free and we get some social good in return.

I'm usually skeptical of moral arguments that don't confront the question of "at what margin" straight up.  I will, however, buy this (abbreviated) argument:

1. A doctor is not required to devote his entire life, or even a part of it, to helping poor kids in Africa, even if he could create greater good by doing so.  Personal autonomy matters.

2. The right to keep the product of your labor -- money! -- is a big part of autonomy, even though it is not always recognized as such.

3. Barring end-of-the-civilized-world exigencies, no one should be forced to part with more than a certain percentage of his or her income, even when valuable public goods are at stake.  There is, after all, no end to good ideas for redistribution, not the least of which is the helicopter drop to Malawi.  We all draw the line somewhere, so it's not enough to cite benevolence to defeat the claims of property rights and the demand for low taxes.

4. Adhering to such a percentage rule will have desirable consequentialist properties, given the public choice problems with government behavior.  Thus a kind of consilience supports this moral view.

That all said, I do not believe we have a very clear or very scientific answer as to what the right percentage is.  Furthermore "the proper percentage" is likely contingent upon historical circumstances.  I take that as representing a partial -- but only partial -- endorsement of Nozick's Wilt Chamberlain argument and of course I reject the deontological ("just don't!") nature of Nozick's approach altogether.

Warning to extreme libertarians: Don't even try to argue that zero is the maximum permissible rate of taxation.  Would you abolish all taxation today, immediately, if it meant a rapid collapse into social chaos?

Warning to social democrats: You are used to citing beneficience arguments to argue for raising taxes.  But you reject beneficence arguments yourself, when you refuse to step into the shoes of Peter Singer and call for even more redistribution.  I want to make you feel guilty about this tension.  What you'd like to do is dismiss Singer with a separate argument and then turn your fire to the anti-tax types and feel that beneficence is always on your side.  It isn't. 

Here is my earlier post on Nozick's experience machine.  Here is Will Wilkinson with more on Rawls.  Going back to our earlier discussion, Ross Douthat has provided an excellent discussion of notable conservative books.  I am a big fan of Nozick's book although a) I don't consider it "conservative," and b) I like the obscure sections best, such as the discussion of anarchy and government in the first part.