What's the point of increasing population if the government
cannot ensure the following :
- Subsidised education for all. And that a decent, minimal level of
education is attained for all;
- Increased productivity, leading to a better, more robust economy.
Higher population does not equate to higher productivity. It could
in fact, drain the economy of resources;
- Traffic, like elindra mentioned. Helloooo traffic congestions and
road rage! 
- Good infrastructure and amenities for all citizens;
etc etc.
It's just going to turn out to be a royal nightmare if this issue
isn't broached carefully, adequate resources channelled, and
appropriate establishment of necessary infrastructure to support
this population growth.
