Rethinking the measurement of food security: from first principles to best practice

While food security measurement has been substantially expanded in recent decades, there persists significant dissatisfaction with existing measurement systems, especially in the wake of the ongoing food and financial crises. In this paper we first set out a list of criteria that an ideal food security measurement system should satisfy. In addition to standard issues of cross-sectional validity, our criteria include inter-temporal validity (the ability to gauge trends and shocks), and nutritional relevance. Using a mixture of literature review and fresh empirical analysis, we then benchmark four types of indicators (calories, poverty, dietary diversity and subjective indicators) against these criteria as a means of systematically identifying their relative strengths and weaknesses, and comparing overall performance. We conclude that, overall, dietary diversity indicators are the best performing class of indicators: they are powerful predictors of economic status and malnutrition (both stunting and wasting), sensitive to shocks, and relatively cheap to measure. Our concluding section therefore also outlines possible steps for scaling up the measurement of dietary diversity (and other indicators) through a mixture of increased funding, greater inter-agency coordination and technological (ICT) innovations that will reduce the cost of high frequency food security measurement.