i never studied economics so I sometimes get lost when economists go technical in their presentations. I just look at regular things I see in the street to gauge how that place is doing economically. when 2 years ago, GM sold more cars in china than in the entire United States I knew that was serious.
Yes it's true. I study economics for my A levels, and I can tell you that economics really is about observing the world and come up with universally understood terms and jargons (among economists) to describe and summarize what is happening in the real world. This is why very often economics theory explain past events best but fails to predict future events. Hence, whenever theory fails, the job of the economist is to observe and extract data in order to improve and perfect the existing model--or complete discard it to build a new one.
Back to topic. Yes the sales of cars is one very important observation. Nowadays real-estate developers use free parking lots that comes with the apartment as a huge selling point. To buy a parking lot in many Chinese cities can cost you from tens of thousands of yuan to hundreds of thousands yuan. To put it into perspective, that's equivalent to most middle class family's annual income in that city, and is often much higher than the price of the car itself.
This just shows how strong the demand for cars is.
Another example I can give is that of roads. In recent years when I went back to my home province Henan (an inland province), I realise most expressways are being upgraded (my province already have over 5,000 km of expressways) to six lanes or even eight lanes. China's expressways are almost all raised above the ground using pillars and enclosed thus it is very costly to widen, but they're doing it nonetheless because current capacity is already not enough and there's often kilometres long of jams on the expressways.
Another example is how urgently the governments are developing subways. When I left my city in 2008 the construction work of my city (an inland provincial capital named Zheng Zhou) only just began. Today the city's first subway line is already operating (41km long), the second line nearing completion, and third and fourth under construction, and the 5th and 6th already planned out. All these will be completed in 2020. Beyong 2020, there are 17 lines already planned out, connecting the city with the New Distrct, Airport, and nearby cities.
This is not just hometown, this is carried out at at least 10 or even more cities countrywide. And this is just subway construction alone.