There's not an objective number for that. But if we assume there is, then you are simply guaranteeing that no rentals will exist, because landlords pay higher taxes than a resident mortgagor, and they have overhead.
Only if you ignore the appreciation on the investment asset (eg the house). That's most of the reason to rent out a house - for the future sale of the property. This would just mean landlords would need to buy the maintenance costs until they sell up.