What happens if they built a city and nobody showed up?

I was watching Al Jazeena America(so far,now just begin to watch by I bit pleasant surprise by Al Jazeena America it has good story and is far less bias then MSNBC)and did a story on new city in China where nobody lives.It seems good housing  is very expensive in China and government sees lots of people from rural area moving to cities,hense,creating a bigger shortage.So government built this new city,problem is speculators have bought into the real estate,hence,driving up the prices.Speculators in Communist country?How did Communism rule China? I mean,the Chinese are born Capitalist even more so than the Jews or Lebanese.
Of course,in nineteen sixties Brazil built Brasilia out of nothing but Rio de Janeiro is still heart and soul of that country and San Paulo is financial center.