There are two theories about China that spell its doom and maybe the United States doom too. One is that they're already lying massively about their population decrease so basically they would be doomed by demographics. There's a theory that when Japan overspent on infrastructure it looked like they were booming but when they stopped spending, they had no GDP growth for many years. The U.S might you know suffer a similar thing where if government stops spending massively as has been recently then maybe we don't have any real growth like it's all been government.