Let me clarify, the increase in housing supply is a reaction towards an increase in AirBNB's and may not cancel out the decrease in housing supply due to those AirBNB's. I made the comment to say the decrease in long term residences is not as great as the number of residences allocated as AirBNB's.

One hotel converted into condominiums create 1100 residences,[1] out of < 30000 AirBNB rentals in NYC. It's such a "problem" the council wanted to ban it. [3]

[1] http://www.marketwatch.com/story/waldorf-astoria-hotel-to-be...

[2] https://news.ycombinator.com/item?id=11992112

[3] http://nypost.com/2015/05/11/council-plan-would-limit-changi...