It is projected that in 2007, for the first time in history, more than half the world's population will live in cities rather than rural areas.

Expert:

  Dr. Eugenie Birch

  Professor and Chair of City and Regional Planning, University of Pennsylvania

Credentials:

Published and lectured widely on city planning issues and contemporary planning and housing

Former member of the New York City Planning Commission (1990-95)

Quote:

"Perceived and actual job opportunities are taking people from rural areas to cities, especially in developing countries.  In Asia, we expect growth from 40% urban to 54% urban in the next couple of decades.  Africa's urban population is expected to grow from 38% to 50% in 2030.  The cities that are capturing the population growth are not the mega-cities of more than 10 million people but smaller cities, which now have 1 to 5 million residents."