The Roaring '20s

As Sarah said in her blog, everyone knows that the twenties were a time when everyone had fun. Everyone partied all the time, organized crime sprung up as a result of the prohibition, and at the end of the decade the stock market crashed and our country entered the Great Depression. However, what I wanted to know about the twenties was how far in advance did the people in charge of money (i.e. the government, banks, etc.) know that we were in trouble? It seems like governments often keep things on the DL until they have no choice, or until something happens; I want to know if they had some advance warning this time and tried to prevent it in secret, and if so, how far before the stock market crash did they know something was going to happen?