That's the benefits of living in the capital of China..also the cost of living is higher in Shanghai..recently there have been reports of people sneaking into the subways in Shanghai..I was uncertain why until I found out that they charge the people in the Shanghai metro per stop and not just a one way ticket like in Beijing. I'm not sure why they do that but I've googled some websites and found that Shanghai ranks above Beijing as one of the most expensive places to live. One other place Hong Kong is more expensive than Shanghai...hope that answers your question somewhat. If I find any more details I'll be sure to add to my answer. 

The simple answer is that beijing Metro subway system has been demonstrated almost projects which were having since last few years.

but in Shanghai still running more then 5 units of Metro subway those are still underconstruction. So income or tax were being paid by local public in term of using the facilities of subway transpotation. Hence Nanjing people also hang out same as similar system of metro admin.

Hope answer of your question. "Simple living & High thinking" 

Ms Irfan

every year Beijing city government subsidizes the public transportation system in Beijing about 17billion RMB . it's about 800Yuan for each resident in Beijing on average .

Beijing is more of a tourist city than Shanghai so they won't have to worry about the amount of money they will be making. . . I would say more tourists visit Beijing than Shanghai which leads to more customers. Afterall, you are a customer of the public transit system in China. 

Because they don't want to charge excessive fees to cars for driving or parking in the city, because that would largely affect the ones making the rules and those who "support" them financially. They're trying to encourage people to take public transport instead of using cars. Years ago when they started building more lines, European city planners told them their plan was idiotic: refuse to put some kind of limit on cars (like London or Tokyo do) and lower the price of public transport and it will have no effect on cars. People will just keep getting them--someone rich enough to afford a car doesn't care of the price of the subway is 2RMB a trip or 15RMB a trip, or if a bus is 3RMB or .3RMB. But people who might otherwise ride bikes or walk part of the way WILL care. They'll say, "Hey, now I can afford to take the bus!" and your public transport will fill to capacity and beyond, while your traffic problems will see no change. 

European City Planners: 1; Beijing Officials: 0

It's heavily subsidized by the government, at least that's what I've heard. Ruthallen's answer above is also correct. It would be detrimental for Beijing to encourage even more motorists.