Economy system after the great depression

After the great Depression, the economy system was destroyed so rapidly. Many people suffered heavy losses in the stock market slump. And the collapse of US stocks in wall street has dealt a severe blow to the world economy. Therefore, people found that the role of government is necessary. By regulating the private enterprises, government exercise political and economy leverage on the companies. When the government regulates the prices, people can get goods in a reasonable price. Also there is a balance of supply and demand.