Three of the Causes of The Great Depression

Today in class we went over some of the causes of The Great Depression. Many problems that arose during World War One were not taken care of properly in the 1920s.While it is consisted the "roaring twenties" it still had problems.
The first argument for the cause is lack of diversification in the American Economy. The American Economy was growing in the 1920s due to two industries, automobile production and construction. The problem with these industries controlling the economy is that people do not need an excessive amount of cars or construction. An example being that from 1926-29 expenditures of construction went from $11 billion to $9 billion. Also, in 1929 automobile sales fell 33%. The problem caused these industries to slow down and people to be fired. No other areas of the economy could compensate. This hurt all industries because people has no money.
Another cause was maldistribution of wealth. There was structural weakness in consumer demand, and profits were not adequately passed on to the consumers. Over 1/2 of American Families lived at or below subsistence level in 1929. Industries over produced products for consumers, the easiest way to recover from this was laying people off. Unemployed individuals would not spend more money, further increasing the issues with the economy. 26% of wealth was controlled by only 2% of the population and 24% was controlled by 60% of the population.
The third cause for the Great Depression was the Credit Structure of the Economy. Banks were able to invest in the stock market, using peoples money, and after the stock market crash they were unable to pay people back. People lost all of their money that was in the bank, even though the people who put money in the bank did not directly invest in the stock market. Corporations also loaned people money in order to make more money, however, when people could not make payments, they stopped making money. The connected structure of borrowing money came crashing down. When one part of the economy failed, it caused all parts of the economy to fail.