Daydream I - The SEC and bank regulators start requiring banks (& such) to disclose how badly their portfolios are impaired by $Pretend/month "rents" that nobody is paying.
Daydream II - When local zoning authorities require ground-floor retail in new developments, but the local vacancy rate for such space is over (say) 5%, then the developer receives a "lease put option" - allowing him to rent that retail space to the zoning municipality at (say) 80% of the then-current local rental rates for similar spaces. If the municipality fails to pay up, it loses its zoning authority.
Daydream II - When local zoning authorities require ground-floor retail in new developments, but the local vacancy rate for such space is over (say) 5%, then the developer receives a "lease put option" - allowing him to rent that retail space to the zoning municipality at (say) 80% of the then-current local rental rates for similar spaces. If the municipality fails to pay up, it loses its zoning authority.