The roots of the crisis from a United States perspective:
To understand today’s financial crisis, you must understand the long history of government interference and subsidies for housing and housing debt.
Since the New Deal, the federal government has passed law after law attempting to shape U.S. housing markets. The U.S. today compels banks to lend to risky borrowers, skews the cost of housing debt and benefit of housing-related capital gains through the tax code, and operates several enormous government lending programs and taxpayer-backed corporations.
1933 – President Franklin Delano Roosevelt issues an Executive Order banning the private ownership of gold coins and bullion under penalty of imprisonment. The government is released from redeeming dollars for gold which makes inflating the money supply much easier.