Org/en/About/Factsheets/Sheecs/20l6/08/01/l6/l 1/Debt-Relief-Under-the-Heavily-Indebted-Poor-Countries-Initiative. Over the past two decades, the growth of world gross product (WGP) on the basis of the exchange-rate-based approach has been below that based on PPP weights. This is because developing countries, in the aggregate, have seen significantly higher economic growth than the rest of the world in the 1990s and 2000s and the share in WGP of these countries is larger under PPP measurements than under market exchange rates.