Does the Choice of Metric Matter for Identifying Areas for Policy Priority? An Empirical Assessment Using Child Undernutrition in India

Ratio-based prevalence and absolute headcounts are the two most
commonly accepted metrics to measure the burden of various socioeconomic
phenomenon. However, ratio-based prevalence, calculated as the number of
cases with certain conditions relative to the total population, is by far the
most widely used to rank burden and consequently for targeting, across
different populations, often defined in terms of geographical areas. In this
regard, targeting areas exclusively based on prevalence-based metric poses
certain fundamental difficulties with some serious policy implications.
Drawing the data from the National Family Health Survey 2015–2016, and
Census 2011, this paper takes four indicators of child undernutrition in India
as an example to examine two contextual questions: first, does the choice
of metric matter for targeting areas for reducing child undernutrition in
India? and second; which metric should be used to facilitate comparisons
and targeting across variable populations? Our findings suggest a moderate
correlation between prevalence estimates and absolute headcounts implying
that choice of metric does matter when targeting child undernutrition. Huge
variations were observed between prevalence-based and absolute countbased
ranking of the districts. In fact, in various cases, districts with the
highest absolute number of undernourished children were ranked as relatively
lower-burden districts based on prevalence. A simple comparison between
the two approaches—when applied to targeting undernourished children in
India—indicates that prevalence-based prioritization may miss high-burden
areas where substantially higher number of undernourished children are
concentrated. For developing populous countries like India, which is already
grappling with high levels of maternal and child malnutrition and poor health
infrastructure along with intrinsic socioeconomic inequalities, it is critical to
adopt an appropriate metric for effective targeting and prioritization.