The Median is the Message: A Good Enough Measure of Material Wellbeing and Shared Development Progress

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We argue that survey-based median household consumption expenditure (or income) per capita be incorporated into standard development indicators, as a simple, robust and durable indicator of typical individual material wellbeing in a country. Using household survey data available for low and middle-income countries from the World Bank's PovcalNet tool, we show that as a measure of income-related wellbeing, it is far superior to the commonly used GDP per capita as well as survey-based measures at the mean. We also argue that survey-based median measures are ‘distribution-aware’, i.e. when used as the denominator of various widely available indicators such as mean consumption expenditure per capita they provide a ‘good enough’ indicator of consumption (or income) inequality. Finally, as a post-2015 indicator of progress at the country-level in promoting shared development and reducing inequality, we propose that the rate of increase in median consumption per capita after taxes and transfers exceeds the rate of increase in average consumption in the same period.

Median consumption per capita has three advantages over commonly used measures of material wellbeing: simplicity and accessibility, durability and relevance as a broad reflection of development as a modernization process.
As a post-2015 indicator of progress at the country-level in promoting shared development, we propose that the rate of increase in median consumption per capita after taxes and transfers exceeds the rate of increase in average consumption in the same period.
The post-2015 development framework should include attention to the logic of good household survey data as a global public good.
Survey-based median household consumption expenditure (or income) per capita should be incorporated into standard development indicators.