santiago:

You can't really compare the value of non-market activities with market activities because each valuation system is mutually exclusive but internally consistent, and that means that you can't really compare Chinese GDP with European, American, or Japanese GDP because the latter countries are no longer in the process of massive rural to urban reorganization that China is now experiencing. You can try to compare actual, physical movements of things such as oil, fertilizer, and raw materials, and the evidence is that China is indeed growing rapidly and probably unsustainably in its use of such things.

Real GDP is incomparable both across time and across countries because it is path-dependent. And nominal GDP is nearly meaningless because of inflation.

The peak-to-trough part of the business cycle is an outlier. Carnot would have died laughing.