What I watch for is the total lack of 'learning' and then I watch what happens when things level off. I watch if a building is being maintained at much slower rates than its decaying.

What might happen is you see that but we also see the brand new supertower going up and say 'Okay.. well look China is still improving overall' but then I watch that new supertower for a year and see how its falling apart and degenerating faster than its being kept up. in less than a year more walls look bad than new. More LED lights are never replaced. More fuckups are done to it than additions. more parts are closed than opening. Watch for that. I dont really mean just buildings either but 'everything' is that way.