The world's richest countries are greying so fast that the combination of fewer workers, lower consumption and the burden of caring for the elderly may doom many to a permanent recession, an expert said yesterday.

   Paul S. Hewitt, director of the Washington-based Center for Strategic and International Studies global ageing initiative, was speaking in Tokyo at the start of the centre's international conference on the problem of greying societies.

   He painted a harrowing picture of the global economy's future as birthrates plummet in Europe, Japan and some pockets of the developing world, such as China. Mr. Hewitt said economic growth in the industrialised world would be paralysed by 2010 unless nations rethought their labour, tax and social policies. "the future is going to be essentially 60-year-olds taking care of 80-year-olds", he said.