LETTERS : Elusive secrets of a successful society

Sir: I must speak out in defence of Sir James Goldsmith against some of the criticism from Nico Colchester ("Pocket guide to beating the trap", 25 January). The statement by Sir James which is the target of his criticism, reads: "The West has impo sed upon the world an obsession with economic growth, but GNP is not the true measure of the success of societies."

Mr Colchester criticises this on the grounds that the UN Human Development Index "correlates crudely but clearly with GDP per head". But this correlation might just as well be used in support of the position taken by the authors of the LTN Human Development Report. They maintain that it is things such as investment in education, literacy and health which help to cause rises in GDP. Mr Colchester, by contrast, uses this correlation to make the opposite point - that increases in GDP are necessary to improve health, education etc.

Yet Mr Colchester cannot prove that he is right rather than the authors of the UN Human Development Index. A correlation does not tell us which way the line of causation runs, and I think the statement by Sir James Goldsmith is completely valid and deserving of full support.

Yours sincerely, H. W. SINGER The Institute of Development Studies University of Sussex Brighton 26 January