i don't know much about the rental market in china, but living there, always renting, i had the impression that rents do not cover the cost of the apartment. it is as if most people rent out their apartment because it would otherwise stay empty. when we finally bought an apartment, the mortgage payments were twice as high as what we would have paid for the same apartment in rent. we had a 15 year mortgage i think, so that means it takes 30 years in rent to just cover the cost of the apartment. is that profitable? i don't know. in germany rent has to be profitable.