Pamella - I did not say it has no impact on the remaining housing stock, I said it has no significant impact on the ability of the remaining housing stock to satisfy newly arising cases of housing need.
There is a difference.
RTB sales are very significantly to the longer-standing social tenants, i.e. those who don't move and vacate their homes for others to rent. Selling off their homes does not significantly reduce the availability of homes to relet.
Selling a "blocked" social home and replacing it with a new one does, on the other hand, provide a new social home for letting to another prospective tenant.
So, in terms of satisfying newly arising housing need it is better to sell of stably-occupied social homes and replace them with new ones than it is to wait for the tenants to die.