alasta:
Redistributing houses between investors and owner-occupiers doesn't really affect the balance of demand and supply in the rental market, all other things being equal.
Wait, you mean when a property investor has to sell a house, it doesn't get bulldozed into the earth and the land red-zoned so no one can ever live there? The way some people are carrying on, you could be forgiven for thinking so.
Every FHB who buys who is currently renting frees up a rental for someone who needs a rental.