New research by RICS concludes that many cities continue to grow at a rapid rate, which poses problems of overcrowding, poor sanitation and chaotic sprawl. But city growth has not taken place as quickly as many expected and the year when the world's urban population exceeds the rural population has been put back to 2007.

Contrary to expectations many cities are coping well with population growth for example Curitiba in Brazil, which has used land use legislation over the past 25 years to encourage high-density quality mixed use development. The research authors conclude that the key to success lies much more in good local government and planning, than it does in central government.

RICS president Peter Fall said: "The mega-city has been perceived as a ticking bomb for decades. Our new research shows not only that the threat has been overstated, but that large urban areas can bring the benefits we all attribute to the best of a 21st Century life, providing decent healthcare, education and employment prospects. While there are still examples of chaos and squalor in oversized in urban areas, there are also working cities that demonstrate that with good government and planning we can get the balance right."