In short, government has been the principal factor preventing the "affordable housing" that politicians talk about so much.
Politicians have also been a key factor behind pushing lenders to lend to borrowers with lower prospects of being able to repay their loans.
The Community Reinvestment Act lets politicians pressure lenders to lend to people they might not lend to otherwise -- and the same politicians are quick to cry "exploitation" when the interest charged to high-risk borrowers reflects that risk.
The huge losses of sub-prime lenders, some of whom have gone bankrupt, demonstrate again the consequences of letting politicians try to micro-manage the economy.
Yet with all the finger-pointing in the media and in government, seldom is a finger pointed at the politicians at local, state and national levels who have played a key role in setting up the conditions that led to financial disasters for individual home buyers and for those who lent to them.
While financial markets are painfully adjusting and both lenders and borrowers are becoming less likely to take on so much risky "creative" financing in the future, politicians show no sign of changing.
Why should they, when they have largely escaped blame for the disasters that their policies fostered?