I&#x27;m not sure I understand the relevance of what Summers is saying. He&#x27;s talking about a current slowdown in growth, and arguing for expansionary monetary policy. This article is claiming that there&#x27;s a limited amount of growth that we can expect in the longterm, because we&#x27;ll run out of sources of energy. But Summers isn&#x27;t talking about energy as a limit..indeed, he&#x27;s saying commodity prices are depressed.<p>Am I missing something?