[GarySpFc]

What do we need them for?

When a country develops a declining birth rate it creates more problems for that society than we can go into here.

[SuzyQue]

Obviously if we were experiencing a declining birth vs. death rate that could be a problem. However, we are not. According to CIA World Factbook: Population growth rate:
Definition Field Listing
0.92% (2005 est.)
Birth rate:
Definition Field Listing Rank Order
14.14 births/1,000 population (2005 est.)
Death rate:
Definition Field Listing Rank Order
8.25 deaths/1,000 population (2005 est.)
http://www.cia.gov/cia/publications/factbook/geos/us.html

So, I repeat, what do we need them for?