Comment by gruez

>Shouldn't you look at the YoY change instead, to compare to stock returns ?

This might work for the G7 case[1], but not the US vs DRC case, where it's an obvious case of sloping up vs sloping down. Granted, the case is contrived, but the original claim was that it was an "mathematical axiom", so it should still hold.

[1] though even in the G7 sample, you can find counterexamples. If you switch to "relative growth" you can clearly see that italy has lagging since the mid 2000s, with no accompanying faster-than-average growth to make up for it. If the claim is that "Historically stocks that had a good run then tended to underperform", then surely the opposite must also hold?