> I argued that this difference is
> caused, for the most part, by individual life choices
> rather than structural systemic factors - a theme that
> you a priori dismissed by your (fallacious) assumption
> of random districbution of status. So your metaphor
> does not realy address the issue that I am arguing.
Individual life choices are not made in a vacuum. At each point in time, our individual choices are *constrained* by natural laws; technology; existing social (economic, legal, political, other) conditions; and the choices other individuals are making at once. All those constraints are structures imposed on the individuals. Of course, one could say that, aside from the influence of natural laws, everything else -- every social institution -- has resulted from choices or actions that concrete individuals have made more or less deliberately at some point in time or another. Yes, but those choices were made already. Some of them by people already dead. We cannot go back in time and start over. Softer or harder, at a point in time, all of those structures are *given* to us.
So, I wasn't trying to answer your question directly. Proving that the social disadvantage of Blacks is structural is like proving a tautology. No need to. You don't deny that the disadvantage exists. You just claim that the disadvantage doesn't result mainly from structures constraining individual choices, but from the individual choices themselves. But that's silly. If we rule out the assumption that Blacks inherently prefer to be at disadvantage, then the disadvantage is structural. This argument has been made, I'm sure, that people love their oppression and "freely" choose to reproduce it.
If that's so, then how did Blacks get to "freely" prefer disadvantages over advantages, bads over goods? If you work your way back in history a few times, you will note that people get to "prefer" their oppression because they've been oppressed! Those choices we make that reproduce our oppression are not free. What we thought was choice is actually well-embedded structure.
If you think in terms of the math of controlled dynamic systems, this dissolution of the structure into choice is trivial. The structure is the initial conditions (y_0) and the laws of motion y_t+1 = f_t(y_t, x_t, ... ), f_t+1 = g_t(f_t, ...), ...). Choice is captured by the controls (x_t). All for t=1, ... Ask where y_0 and the rules y_t+1 = f_t(y_t, x_t,...), f_t+1 = g(f_t, ...), ... came from, recursively, over and over, and you'll be pushed back to the point when the human intelligence (or the universe!) was born, that is, when y and x were one and the same mush.
The real issue here is how hard or soft the structures are to the immediate agency of individuals. What I was trying to do with my Rawlsian argument was help you sense how hardwired the structures that constrain the individual choices of Blacks in the U.S. really are. An average Black child about to be born is at a disadvantage from the onset compared to an average White child. What bad decisions did the Black child make to produce that outcome? Or what good decisions did the White child make to produce that outcome? You cannot include the decisions of the parents here, because those choices already become structure for the baby. If your mother didn't take care of herself during your pregnancy, that may have imposed very hard (biological) constrains on your individual choices. If your parents were poor when you were a baby or toddler, your brain got "poisoned" and your learning skills diminished (according to a recent study reported by the Financial Times). Etc.
So, obviously some of the structures that constrain the individual choices of Blacks are deeply ingrained in our societies. Again, the question is, are the *main* structures constraining the choices of Blacks in the U.S. biological (e.g. genetic health), economic (e.g. economic discrimination), legal (e.g. civil right laws are not duly enforced), political (e.g., a lower degree of political representation and involvement), or socio-psychological (e.g., it's something about Black culture or collective psychology)? Neither of them is immutable. Of course, ultimately, if Blacks (or any other oppressed demographic group for that matter) are to expand their freedom, they will have to start by changing their individual choices, which if sustained will lead to changes in their collective psychological makeup, which at some point will expand their political power, which will lead to more favorable legislation and its enforcement, which will eventually alter their collective economic opportunities, which will translate in permanent gains in health. But that doesn't make the individual choices they have to make today any freer or easier.