From Prof Sanjay G. Reddy.

Sir, Albert Keidel notes (“The limits of a smaller, poorer China”, November 14) that new data on price levels prevailing in China suggest that it has a smaller economy than widely believed until now, and that levels of poverty are higher than had been thought. This comes as no surprise to many of us who have argued that the World Bank's use of outmoded and inappropriate purchasing power parity conversion factors to assess poverty and to estimate the relative size of national economies should be viewed sceptically, especially in the case of those countries such as China and India that have not participated in comprehensive price surveys for a very long period of time, if ever.