I don't have any data to back this up, just knowledge about Chinese society. My view is the main driver for the low score for China is the society norm of mindi

I don't have any data to back this up, just knowledge about Chinese society. My view is the main driver for the low score for China is the society norm of minding your own business and not getting involved. So it might not be a measure of honesty but rather a measure of being passive. For example, I would assume if instead of having to contact the person, the person just walked over to retrieve the wallet, they'd likely get it back.