- Consequences of population growth - Growing cities [SLIDE 1] The increase of wealth in developed nations as compared to conflict and population growth in poor nations has led to migration, an increase in refugees, and other challenges. U.S. immigration laws admit 1.2 million new immigrants per year. This accounts for 35% of all of its population growth. The United States admits more people than all the other wealthy nations combined. Most immigrants contribute to the economy via productivity. There have been illegal immigrants especially from Mexico and southern regions of the world that have been associated with drug trafficking and other crimes. This is also a sensitive political issue. [SLIDE 2] Some areas of the world are growing at a much faster pace than the rest of the world. The top 10 growing cities include: Tokyo, Japan Delhi, India Sao Paulo, Brazil Mumbai, India Mexico City, Mexico New York-Newark, USA Shanghai, China Calcutta, India Dhaka, Bangladesh Karachi, Pakistan Poorer areas also have growing slums outside city limits that do not get city support and thus lack basic sanitation, electricity, housing and other needs. Crime and violence happen in these areas without much oversight or police participation. People in these areas also lack basic drinking water and education and healthcare.