What on earth are you on about? He said they did not save during boom times, so it is a human mistake, not some collapse of empire ( I didn't know America is an empire btw, I thought it was a country.)
What you need to realize is that a minuscule percentage of economists will agree with your "saving during boom times". The money system just doesn't work like that.
As I said, my second part was reactionary to his moniker in relation to his comment, his comment is populist rhetoric and is completely incorrect from a strictly capitalist view.
People who call themselves capitalists should at least bother to get it.
But it seems that wikepedia agrees with me:
"Politically, an empire is a geographically extensive group of states and peoples (ethnic groups) united and ruled either by a monarch (emperor, empress) or an oligarchy. Geopolitically, the term empire has denoted very different, territorially-extreme states"