> one thing that ought to be pointed out is that free
  > markets tend to punish companies, over the long term,
  > that intentionally deny themselves access to talent
  > due to bigotry.

If this happens on a large enough scale, then it's hard to quantify. If this happens enough that it keeps the number of women in tech low, then how can you really quantify what they are missing out on? It would be easier to quantify if there was a large number of skilled female programmers, but if they are discouraged from even reaching the point of becoming skilled/competent programmers...