That seems like a disingenuous question and the generally accepted answer is on the same website you linked: <a href="http:&#x2F;&#x2F;www.tradingeconomics.com&#x2F;japan&#x2F;population" rel="nofollow">http:&#x2F;&#x2F;www.tradingeconomics.com&#x2F;japan&#x2F;population</a><p>Fewer people = less growth