Why are there so many poor people in America?

The economic crisis has led to an increase in the number of poor people in the United States and a high unemployment rate. The official unemployment rate is 9%, which actually exceeds 14%. The American people have little savings. They all live on loans. As soon as the middle class loses its job and receives unemployment benefits for half a year, it immediately becomes poor, or the poor in debt. Otherwise, how could the Occupy Wall Street movement break out? Many of those demonstrators were supposed to be middle class, but many of them graduated from universities, and many of them were masters or even doctors from prestigious schools. They just can't find a job, but they find a part-time job with low income, and they all have tens of thousands, hundreds of thousands or even hundreds of thousands of college loans. I don't know when I can pay it off. Moreover, if you don't have a full-time job, you won't dare to see a doctor without medical insurance, and the hospital won't show it to you without insurance. Therefore, the economic crisis has led to fewer and fewer middle classes in the United States, and many of them have become poor people with negative assets.

Why do many people change dollars into RMB? In fact, the purchasing power of 1 USD and 1 RMB is similar. You can't ask the American people to earn dollars and then spend them in China.