http://marketurbanism.com/2016/06/27/do-the-rich-cause-high-...
I did some calculations a few months ago; if every wealthy person in NYC bought 10 homes, that would have the same (negligible) impact on the housing supply as building another NYU.
https://news.ycombinator.com/item?id=12022235#12022920
This is not an effective use of public policy. It's just an attempt to find a scapegoat while ignoring the real problems - exclusionary zoning, low density and bad local regulations.