Homebuilders - The hypothesis if correct should show up in relative movement of housing prices between city and outside beltway.
Arbitraging the difference between city and outside-beltway property pricing probably ought to allow for people to make the change, assuming they own in the city to begin with.
Not sure how many people really have the $$ for a downpayment if they can't free up cash by selling a property they own first
Where powers are assumed which have not been delegated, a nullification of the act is the rightful remedy: that every State has a natural right [...] to nullify of their own authority - Thomas Jefferson