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# **I. Introduction**

Major progress has been made over the last 30 years in reducing the prevalence of malnutrition amongst children. Between 1970 and 2000 the proportion of malnourished children was reduced by 20 % in developing countries [1, 2]. Despite this, approximately 27% of children under the age of five in developing countries are still malnourished [1]. Malnutrition currently claims about the half of the 10 million deaths each year among under-five children in the developing world, and is the risk factor responsible for the greatest loss of DALYs'globally, accounting for 16% of total DALYs [3]. Furthermore, malnutrition is highly associated with poverty-levels of malnutrition are higher in poor countries than in better-off countries. In low income countries 36 % of children are malnourished compared with 12% and 1% in middle income countries and the United States, respectively [4]. There is also growing evidence (see below) that, _within countries,_ the poor suffer from higher rates of malnutrition than the nonpoor. This has led for calls for the focus to be on reducing levels of malnutrition _amongst the poor [5-_ 7]. And yet the goals and targets of international development and bilateral aid agencies continue to be couched in terms of improving population averages [8]. For example, the only nutritionfocused target of the OECD's Development Assistance Committee (DAC) is couched in terms of population averages-to reduce the proportion of children under-five who are underweight by one half between 1990 and 2015 [9].

Part of the reason for this gap between rhetoric and reality is lack of data-until recently, only patchy data existed on poor-nonpoor differences in malnutrition rates. This is now changing. Two recent studies of malnutrition in Africa [10, 11] documented the gaps in malnutrition across consumption groups in that continent, while a new dataset [121 allows comparisons to be made across 48 countries of malnutrition differentials across quintiles of "assets".

This paper contributes to this growing empirical literature on poor-nonpoor inequalities in child malnutrition. It differs from the aforementioned studies in a number of respects. First, by using concentration indices and corresponding standard error estimates, it attempts to draw systematic conclusions about cross-country differences in malnutrition inequalities. In this respect, the paper is the analog for child malnutrition of the analysis of inequalities in infant and under-five mortality reported in Wagstaff [13]. The results in the present paper suggest that several countries have high inequalities on more than one indicator of malnutrition, while several have low levels of inequality. We also find, however, that in many of the pairwise comparisons between countries, the differences in inequality are not statistically significant. Second, we present some evidence-albeit very limited-on the issue of why some countries have higher levels of inequality in malnutrition than others. Specifically, we explore the possibility that inter-country differences in inequalities in malnutrition reflect inter-country differences in inequalities in consumption. Third, we emphasize the evidence on both inequalities _and_ population averages. We find some countries that do well on both dimensions, but find many that perform well on one dimension but badly on the other. We therefore go on to compute values of a summary index that captures how well a country does both on its average rate of malnutrition and on its inequality in malnutrition. We find some swapping of positions-