I generally follow the logic. Though, if salaries are not enough to support a mortgage application this model will trap people in a renting cycle. A precarious one at that. The interesting part in the model you present is the use of investment portfolios to get on the housing ladder. Its as if working hard isn't enough, you need some extra device, with a degree of risk and luck to make the leap to home ownership.

Its great to imagine what would happen if people couldn't buy second homes, or being innovative over how a special tax rate could be applied to young people. No-one really knows the answers until it happens. My gut feeling is that renting is unethical - I know I couldn't bring myself to make money out of someone renting if I had my own house and enough money already. But that's it, none of these issues are based on isolated models.

My crude knee jerk ideas: A maximum cap on rental prices indexed to minimum wage.

A preference model where first time buyers get 1st picks.

A trusted simple well thought out online platform that makes buying and selling a house as easy as possible (replacing the trickery of estate agents).

And for Landlords: Absolutely robust laws always favouring the right of the tenant, so landlords are forced to acknowledge a social responsibility to their tenants - what bigger responsibility could you have for another human being then being a Landlord.

An online platform where tenants can request references on Landlords from old tenants.