A good supply side interpretation of events. Of course the supply siders fail to mention that it was their policies that got us into this mess.
I think the analysis provided is rather narrow and uninformed. By the way I teach this stuff at the university level.
Much of the debate is did the new deal work.
I think this has to be addressed in both economic and political terms.
Europe reacted to the Depression with communism, fascism, Nazism and totalitarianism. Of the big powers only Great Britain and to a certain extent France preserved democracy and capitalism.
FDR knew what was happening in Europe and his New Deal was designed to preserve capitalism and democracy. He realized the need for a social net and created SS to provide for it. He put people to work through things like the CCC, NRA, etc.
For the economic success see:
http://money.usnews.com/money/business-economy/articles/2008/04/11/did-the-new-deal-work?pageHere is another and much more complete set of reasons for the Great Depression:
1. Stock Market Crash of 1929
Many believe erroneously that the stock market crash that occurred on Black Tuesday, October 29, 1929 is one and the same with the Great Depression. In fact, it was one of the major causes that led to the Great Depression. Two months after the original crash in October, stockholders had lost more than $40 billion dollars. Even though the stock market began to regain some of its losses, by the end of 1930, it just was not enough and America truly entered what is called the Great Depression.
2. Bank Failures
Throughout the 1930s over 9,000 banks failed. Bank deposits were uninsured and thus as banks failed people simply lost their savings. Surviving banks, unsure of the economic situation and concerned for their own survival, stopped being as willing to create new loans. This exacerbated the situation leading to less and less expenditures.
3. Reduction in Purchasing Across the Board
With the stock market crash and the fears of further economic woes, individuals from all classes stopped purchasing items. This then led to a reduction in the number of items produced and thus a reduction in the workforce. As people lost their jobs, they were unable to keep up with paying for items they had bought through installment plans and their items were repossessed. More and more inventory began to accumulate. The unemployment rate rose above 25% which meant, of course, even less spending to help alleviate the economic situation.
4. American Economic Policy with Europe
As businesses began failing, the government created the Smoot-Hawley Tariff in 1930 to help protect American companies. This charged a high tax for imports thereby leading to less trade between America and foreign countries along with some economic retaliation.
5. Drought Conditions
While not a direct cause of the Great Depression, the drought that occurred in the Mississippi Valley in 1930 was of such proportions that many could not even pay their taxes or other debts and had to sell their farms for no profit to themselves. The area was nicknamed "The Dust Bowl." This was the topic of John Steinbeck's The Grapes of Wrath.
I would add the following. between the end of WWI and 1921 the nation shifted from being an agricultural economy to an industrial one. Prior to WWI some 80 percent of labor worked on the farm and as industrialization took hold only 20% were needed on the farm. Many of those who came from the farm were not equipped to work in a factory. Thus, endemic unemployment became a problem. Something that is happening now. Many of those in our labor force are not equipped to work in biotechnology, silicon valley type industries, etc.
for an analysis of the FDR response see:
http://www.nytimes.com/2008/09/18/business/worldbusiness/18iht-strategy.4.16288248.html?_r=1&pagewanted=allAlso see:
http://lachlan.bluehaze.com.au/books/galbraith_1929crash.html