It is the sort of bulge in the numbers of people in productive age groups that produced explosive growth in China and South-East Asia.
Workers are now at their most productive age, he said.
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Between 2m and 3m of the country's 40m people are thought to be infected and most new carriers are in the most economically productive age-group of 15 to 40.
"He is a star of the field, one of the most productive people in his age group, " says Princeton University's Kahneman, who won the 2002 Nobel Prize in economics.
And entire industries have grown up around the idea of productive aging, the third age, or all the other marketing euphemisms out there.
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When children are allowed to develop their mental abilities at a young age, it can be very productive in future.
Cardiff fan Ledley, who has been at the club since the age of nine, graduated through the productive Bluebirds youth academy and was named alongside Johnson in the Professional Footballers Association's Championship team of the year last season.
Art lovers might think that the age at which painters are at their most productive is determined by their style, experience and personal development.
The industrial age spurred people to be passionate, creative, brilliant, and more productive and wealth-producing than ever before.
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Meanwhile, however, the literacy rate among men of working age has risen to 70%, making the labour force much more productive than in the past.
There have been claims that the move towards encouraging children to begin learning at an early age is "too much, too soon" - and that it can be counter-productive.
After seven productive seasons, which included All-Pro honors in 2007 and 2008, he had earned the right, at age 28, to cash in big.
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