Reply to Katie:
You still have not provided one example of a bubble that was not preceded by money supply intervention.
An argument can be made that Senator Obama's Affordable Housing act loosened lending standards such that the bubble was channeled into housing; instead of, say Mining and resources.
The bubble would have existed somewhere.
The fact that Obama was complicit in building so many houses that his act should be called the 'Boardable Housing Act' does not take away the point that the original cause was the expansion of the money supply.
19th Century
Panic of 1819, a U.S. recession with bank failures; culmination of U.S.'s first boom-to-bust economic cycle
Panic of 1837, a U.S. recession with bank failures, followed by a 5-year depression
Panic of 1857, a U.S. recession with bank failures
Long Depression (1873–1896)
Panic of 1873, a US recession with bank failures, followed by a four-year depression
Panic of 1884
Panic of 1893, a US recession with bank failures
Panic of 1896
20th century
Panic of 1901, a U.S. economic recession that started a fight for financial control of the Northern Pacific Railway
Panic of 1907, a U.S. economic recession with bank failures
All occurred prior to 1913 when the Federal Reserve was created. All occured while we were on a metal standard for currency, e.g. all U.S. currency was backed by gold, which meant that there was a finite amount of money in the system. None were really caused by money policy intervention. All were caused by poor fiscal discipline by investors and banks.
Additionally, the roots of the sub-prime mortgage crisis had nothing to with anything that Obama did, either as President or Senator. The beginning was in 1993. In 2004 "Following example of Countrywide Financial, the largest U.S. mortgage lender, many lenders adopt automated loan approvals that critics argued were not subjected to appropriate review and documentation according to good mortgage underwriting standards." (from a Wikipedia article)
That conjecture proved to be extremely true and accurate as the sub-prime market was saturated with loans that were not sustainable.
It's not so much money supply intervention as it is stupid greed, and poor due diligence.