The Chinese yuan, also known as the renminbi, is already convertible under the current account - the broadest measure of trade in goods and services. However, the capital account, which covers portfolio investment and borrowing, is still closely managed by Beijing because of worries about abrupt capital flows.
Last Wednesday was a day like any other for Liu Kang, a 35-year-old migrant worker from Anhui province . He rose at 6am from the bed in the dormitory he shares with a dozen other migrant workers. His boss charges him 50 yuan a month for using the bed.
Breakfast is a glass of water and a piece of fried dough, costing 2 yuan, before he starts a gruelling 12-hour day of delivering mattresses on a three-wheeler from the factory on the outskirts of Shanghai to customers all over the city. In the mornings, he loads eight mattresses on to his trike and negotiates his way through the noisy traffic. Lunch is a box of rice and vegetables, costing no more than 5 yuan. He works seven days a week.
Mr Liu's wife and son live an eight-hour train ride away in a village in Anhui, a poor rural province. He sees them once a year, when he returns for the Spring Festival. 'Life is very hard but I have no choice,' he said. 'If I work the land at home, I earn next to nothing because of the cost of fertiliser and taxes. At least here, I can save a few yuan each month and send them home.'
Also last Wednesday, as Mr Liu delivered his mattresses, Victoria Beckham, six months pregnant, arrived for her second visit in five weeks. The wife of soccer star David stayed three nights at the Four Seasons Hotel, where the cheapest room costs US$260 a night. She attended a model competition arranged by a big cosmetics company and a charity event, where tickets cost at least US$100 each. On her first trip to the city, in October, she was a judge for the World Elite Pageant Final, part of Shanghai Fashion Week, along with Maggie Q, Maggie Cheung and basketball star Yao Ming.
The worlds of Mr Liu and Mrs Beckham did not meet; but their presence reminded me of the postcards sold in city hotels before the Japanese invasion. In one, two dozen rickshaws - similar to the one that Mr Liu pedals - are parked on a narrow street near the Bund. Others carry rich Chinese and European women wrapped in the elegant, colourful dresses that Mrs Beckham would have worn if she had been here at that time. The rickshaw man and his passenger probably did not talk, but were interdependent. The man earned his fee from the woman, and it was his cheap labour - and that of millions like him - which created the wealth from which the woman lived.
In the same way, the participants at Mrs Beckham's model competition and charity event could afford to take part because they run factories which pay a wage similar to Mr Liu's to people from villages like his. And they save money thanks to the cheap products and services which those workers provide. So just what was the communist revolution about?