I believe the gp is saying that BI won't cause a redistribution of consumption from the high-end to the low-end, but instead of redistribution of investment on the high-end (since consumption doesn't scale linearly with income - probably something logrithmic looking), and this loss of investment will have a much greater negative effect on productivity than any minor increase due to consumption on the low end.
Yes, I think at this point it's really just a difference of opinion as to what the effects of BI would be. My view is that the marginal utility of those dollars spent by the high end on investments is lower than the marginal utility of increased consumption at the low end, especially as the actual amounts involved are not that big. I guess the best way to resolve the issue would be experimental validation! ;-)
