I’m confident the Indian and Chinese exceed this by far.
Your confidence is misplaced.
According to any research by any organisation you care to mention you're wrong. The US worker is the most productive on earth, by far. In certain sectors, China's most productive industries are approaching Japan's productivity, was lags the USA by about 8% (a very significant margin, if you understand how producivity leverages economic performance). The best Indian industries are even further behind. This is true despite the dollars decline in relative terms.
(You are wrong because I suspect your impressions are gleaned from the mass media and general hype about India and China's industrial growth over past decade. Yes they have surged in high percentages, but off a tiny base in comparison to the USA. Despite the ignorant hype of many commentators, China is not nearly close to world economic dominance. It was ony recently that China's entire economy surpassed Italy's, with a rather large population disparity.)
International Labor Organization Their Factbook 2008 is an invaluable source.
Latest ILO report: "What’s more, the report also shows that the productivity gap between the US and most other developed economies continued to widen. The acceleration of productivity growth in the US has outpaced that of many other developed economies..."
One of many reports by REITI (Research Institute of Economy, Trade, Industry), and
another
UK Govt paper on international productivity comparisons
One of many OECD reports
... there are hundreds more. Can you cite any authoritative sources to back your claim?
In the period 2000-2006 only Taiwan, Sweden and Korea had productivity
increases greater than the USA, but in overall productivity per worker in virtual all sectors the USA leads the world. Remember,
productivity increases measure only productivity growth relative to previous levels obtaining in that country, not the actual productivity in comparison to other countries. Thus Burundi for example can lead the world in productivity increase but still be only one-fortieth as productive as say a Japanese worker.
The general nonsense peddled about the USA economy is staggeringly naive, so it's little wonder people suffer from misapprehensions. It's astonishing how many people genuinely think the USA economy consists largely of do-nothing managers sitting in offices shuffling paper, and hamburger-flippers and 7/11 checkout clerks. They forget that when Americans (and their media) complain about exported manufacturing industries, for example, or the "gutting of America's industrial base", they are speaking in comparative terms the rest of the planet can barely comprehend. America's domestic manufacturing & industrial base is still by far the largest, most productive and most profitable on the planet, and by a very long measure. Even with the rise of China and India, America remains the 900lb gorilla in industrial output.