For each of the three social indicators used in the tables on National Peformance Gaps, deriving an expected level of performance requires the fitting of a line to country data represented by points on a graph of which one axis is always GNP per capita.

The graph on the right, using only 11 countries for the sake of clarity, illustrates this process in the case of the under-five mortality rate (U5MR). Indonesia, for example, is represented as a point with a GNP per capita of $880 and a U5MR of 80. Once the position of all countries is plotted in this way, the fitted line representing average achievement is derived by the method of least squares and clearly demonstrates that child mortality decreases as GNP per capita increases.

It is this line which provides the expected value of U5MR for each country given its GNP per capita. With a GNP of $880, for example, Indonesia would be expected to have a U5MR of 60. Indonesia's actual U5MR is 80, 20 points more than expected, yielding a National Performance Gap of 20. By contrast, Egypt (GNP per capita $710) could be expected to have a U5MR of 76 but has an actual U5MR of 52, leading to a positive National Performance Gap of 24.

The National Performance Gap shows that some countries have achieved considerably more social progress than others at the same level of per capita GNP. Honduras, for example, is doing better than Senegal, Zimbabwe better than the Sudan, and Mongolia better than the Lao Republic, even though these pairs of countries have similar GNP per capita.

SOURCE Under-five mortality: UNICEF. GNP: World Bank, The World Bank Atlas 1996.