Shanghai has been described as the "showpiece" of the booming economy of China. The city is a global center for finance and innovation, and a national center for commerce, trade, and transportation, with the world's busiest container port—the Port of Shanghai. , Shanghai had a GDP of () that makes up 3.85% of China's GDP, and a GDP per capita of (). Shanghai's six largest industries—retail, finance, IT, real estate, machine manufacturing, and automotive manufacturing—comprise about half the city's GDP. In 2019, the average annual disposable income of Shanghai's residents was () per capita, making it one of the wealthiest cities in China, but also the most expensive city in mainland China to live in according to a 2017 study by the Economist Intelligence Unit.