the other reason would be the whatever you subsidize you just get more of that. So in an market based system prices generally rise until they have balanced out

the other reason would be the whatever you subsidize you just get more of that. So in an market based system prices generally rise until they have balanced out the gains from tax deduction (interest & prop tax). Also, given the amount of labor force mobility in US now vs 30 years ago it anyways does not makes sense to force people to 'settle down'.