China has steamed past Japan to become the world's second-largest economy. Japan's economy, hit by a drop in exports and consumer demand, was worth $5.5 trillion at the end of last year, while China's was estimated at $5.8 trillion. China is expected to take over the US as the No. 1 economy in about a decade, reports the BBC. Japan officials played down the news. "As an economy, we are not competing for rankings but working to improve citizens' lives," said the nation's economics minister.