China's top three municipalities of Beijing, Shanghai and Tianjin have become advanced urbanized societies, according to the China Urban Development Report 2012.
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The report, released by the Institute of Urban and Environmental Studies at the Chinese Academy of Social Sciences on Tuesday, said the population distribution between rural and urban areas is a key indicator of the urbanization level of a country or region.
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If the urbanization ratio of the population is between 51 and 60 percent, then it's a primary urbanized society. A medium urbanized society is between 61 and 75 percent and advanced between 76 and 90 percent.
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China's top three municipalities of Beijing, Shanghai and Tianjin have entered this bracket, according to the report.
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A ratio above 90 percent indicates a complete urbanized society.
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It also says China needs to spend 4 to 5 trillion yuan ($786 billion) to provide social security and public services for 400 to 500 million new urban residents in the next 20 years.
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