You have to keep in mind that this economic migration to and from cities is something that's been happening for centuries and likely since the beginning of human civilization. The US is a particularly great illustration of this since it's such a new nation. Every single city in the US was a remote backwoods not all that long ago. And then the same process happens over and over. Some city begins to attract more and more people. This results in development and growth. Those that succeed during this period rise to the top and thrive. Some of those that do not move on and try to take part in what becomes the next great opportunity.
Take San Francisco for instance. The thing that brought it from being a backwoods to a major city was the gold rush of 1849, which is also where the name of the football team 'The San Francisco 49ers' comes from). You get a huge influx of people, lots of money and resources flowing, and the next thing you know it's one its way to becoming one of the largest cities in the US with massive growth.
However, the opposite can also happen. For instance Detroit used to be one of the most desirable cities in the US. It was the 4th largest city in the nation with a surplus of great high paying jobs. This wealth and opportunity ended up attracting vast numbers of people - more than there was opportunity for. And then on top of that what jobs and opportunities there began declining. And next thing you know people are leaving the cities and droves and today it's home to countless empty buildings, the second highest crime rate, and one of the highest unemployment rates in the country.
In the end the point is that cities, and the demographics within them, are in constant shift. Thing's change over time and it's always up the individual to find where the greatest 'value' is, with the meaning of 'value' certainly varying quite heavily from person to person.
Take San Francisco for instance. The thing that brought it from being a backwoods to a major city was the gold rush of 1849, which is also where the name of the football team 'The San Francisco 49ers' comes from). You get a huge influx of people, lots of money and resources flowing, and the next thing you know it's one its way to becoming one of the largest cities in the US with massive growth.
However, the opposite can also happen. For instance Detroit used to be one of the most desirable cities in the US. It was the 4th largest city in the nation with a surplus of great high paying jobs. This wealth and opportunity ended up attracting vast numbers of people - more than there was opportunity for. And then on top of that what jobs and opportunities there began declining. And next thing you know people are leaving the cities and droves and today it's home to countless empty buildings, the second highest crime rate, and one of the highest unemployment rates in the country.
In the end the point is that cities, and the demographics within them, are in constant shift. Thing's change over time and it's always up the individual to find where the greatest 'value' is, with the meaning of 'value' certainly varying quite heavily from person to person.