Tianjin is the Philadelphia of China

Philadelphia has about 6 million people in its metro area, and is the 5th largest metro area in the country.  It was the first capital of the US before it was moved to Washington, 139 miles away.  Amtrak connects the cities.  It has a stock exchange and is the headquarters to several Fortune 500 companies.  The Comcast Center was completed in 2008 and is 297m tall.  Philadelphia is an important medical research center, and many pharmaceutical companies operate there including: GlaxoSmithKline, AstaZeneca, Wyeth, Merck and Johnson and Johnson.

Tianjin has 4.3 million in its urbanized area, and 10.3 million in its metro area (another source says 6.6 million), making it the 6th most populous city.  It is 87 miles from Beijing, and high-speed rail connects them.  Several supertall buildings are under construction, and one of them (Goldin Finance) is almost 600m. "Tianjin pillar industries comprise of electronic information technology, automotive, bio-tech and pharmaceuticals, metallurgy and petrochemicals industries."

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Update:  Wouldn't Baltimore be a better comparison?  Baltimore is the sister city to Washington like Tianjin is to Beijing. Although Baltimore is depressed and Tianjin is booming.  So I am sticking with Philadelphia as a comparison.