Do you have any links to some studies that have tried to weigh up the positives and negatives in modern China? Especially how the positives have not been equal

Do you have any links to some studies that have tried to weigh up the positives and negatives in modern China? Especially how the positives have not been equally shared. I know it's an annoying question but there are a lot of millionaires in China however maybe the '0.1%' getting all the money in China is actually 0.2% rather than 50%