Follow up question for history

The first pargraph is what i wrote, and the second paragraph is the follow up question the instructor asked me that needs to be answered:
 
ME:
During 1920s, the economy of United Stated was very poor and there was a collapse of the economy that was described as Great Depression. The Great Depression did not at once and also it was not caused by only once thing. One of the main domestic causes of the Great Depression was that the economy of the United States operated openly, and the wealth of the United States concentrated in few hands. Only one percent of the people owned one third of the all American assets. The concentration of the wealth in few hands cased the economy to slow down and the middle class people has also stretched their limits loans for purchasing vehicles and appliance for their homes on installment basis. Other reason was that the banks system and structure was week. Banks were advancing loans without proper security. Before the crash of stock market, the banks could advance any kind of loans without any investigation of the client’s ability to pay out loans because of the lack of regulations. After the stock market crash, the Americans were not able to pay their mortgages and loans. Third cause of the Great Depression was industry and agriculture. The prices of the agricultural products were already low because the farmers were not able to spark any kind of recovery which has direct effect on the industry as the industry inputs were shorten because of the failure of the agriculture sector. In these conditions almost five thousand  banks in the United States failed and hundreds of thousands of people lost their jobs.
 
 
Follow up:
Shawn, you mentioned that the banks were giving out loans without much research into if a person could pay it back. It seems that recently this occurred again and is still occurring. Why is this allowed to occur? Should it be?