Final answer:
The banking industry contributed to the 1920s economic boom by making credit more accessible, enabling increased consumer spending on goods and encouraging investment in stocks and real estate, though it also resulted in high debt and wealth disparity.
Step-by-step explanation:
The banking industry supported the economic boom during the 1920s by making it easier to borrow money, which led to an increased demand for cars and other high-priced goods. This was part of a broader expansion of consumer credit and the adoption of buying on credit or 'carrying' debt.
The availability of credit fueled mass consumption and enabled more Americans to afford goods like automobiles and appliances that were once considered luxury items. Additionally, bank loans facilitated a rise in real estate speculation, and the stock market benefitted from practices such as buying on margin, where investors borrowed money to purchase stocks. While this credit expansion contributed to the economic boom, it also led to high levels of debt and an uneven distribution of wealth, setting the stage for economic difficulties in the future.