We must find a more useful way of expressing GDP growth than percentages, which express acceleration but contain no useful information by themselves.

They don't tell us, for example, that China's current 6.5% 'growth' rate produces much more growth than did the 12.7% rate Prof. Roach refers to.

China's PM Li discussed this last year: "China used to grow at double-digit rates, but now the growth has moderated to a medium-high level of 6.9 percent in the first quarter of this year. Some characterize this trend as a slowdown, but that wouldn't be very accurate, as the Chinese economy has become much bigger than before. Every one percentage point of growth in GDP now would generate the same amount of additional output as 1.5 percentage point growth five years ago or 2 percent growth 10 years ago. I often use the analogy of somersaults to describe such a situation: It is much easier for a child to do a dozen somersaults at one go than for an adult, for whom just three or four would be quite an accomplishment. For major economies with GDPs of $2 trillion or above, a 3 percent growth would be no mean feat. I hope you can view the Chinese economy in an objective way. It will keep growing at medium-high speed, as we have 1.3 billion people, huge market potential and social creativity".