[DoreenMichele]

In addition to other pertinent points being made here:

1. People who have lived someplace a long time and love that place may not want to leave. They may want to try to resolve their problems where they are.

2. Once you are homeless, relocating can be extremely challenging. You may not have the money to pay for bus or train tickets, you may have no means to line up a job elsewhere first, etc.

3. Big cities are where the services are. If you are completely destitute, being in a big city can help you stay fed and clothed.

So it only makes sense to leave the big city if you have some unearned income that will go further if you live someplace cheaper. If you are unemployed and destitute with no prospects, the big is a better answer than a small town because you can at least get a free meal regularly.