How did "The Great Depression" start?

Robert Mcelvaine describes the unequal distribution of consumable income as the primary cause for the depression. During the 1920s and 1930s, the economy largely depended on consumer spending. Since income was distributable among the few individuals, demand for consumer goods declined sharply crumbling the economy. Many people were not able to afford commodities implying that the companies and other businesses could not sell their goods. Due to highly reduced sales, businesses were unable to service their loans and the financial sector collapsed.