1. US GDP per capita is still almost 8x that of China: $53,042 US vs. $6,807 China (http://data.worldbank.org/indicator/NY.GDP.PCAP.CD). While there are other ways to measure this (such as the PPP Sam cites), the magnitude of difference remains large. So even if China's economy in the aggregate is larger than the US's, the US is still much richer per capita.
2. As China grows richer, I expect the US will too. In modern inter-connected economies with few trade barriers growth in one generally benefits the other too. One example would be as one country's citizens gain greater purchasing power, they become bigger consumers of the other country's goods and services.
1. US GDP per capita is still almost 8x that of China: $53,042 US vs. $6,807 China (http://data.worldbank.org/indicator/NY.GDP.PCAP.CD). While there are other ways to measure this (such as the PPP Sam cites), the magnitude of difference remains large. So even if China's economy in the aggregate is larger than the US's, the US is still much richer per capita.
2. As China grows richer, I expect the US will too. In modern inter-connected economies with few trade barriers growth in one generally benefits the other too. One example would be as one country's citizens gain greater purchasing power, they become bigger consumers of the other country's goods and services.