1. An open immigration policy helps countries solve many of the problems by a low birthrate.
2. The unreasonably high cost of real estate means that living space is very limited.
3. As women gain equality and independence,they are free to pursue careers and postpone childbirth.
4. Economic decline will occur when there are too few workers to support the economic activity.
5. The US government forecasts that white Americans will be a minority by 2042.