This article is concerned with the affordability gap, or as the authors put it, the magnitude of the gap between food expenditure and the lowest cost of meeting nutrient needs. A visualisation of the affordability gap can be seen in Figure 1. The study uses primary data and examples from the Fill the Nutrient Gap (FNG) analyses, developed by the World Food Programme, to demonstrate how the affordability gap can be useful in designing intervention programs aimed at making nutrient-adequate diets affordable. The study looks at the Dominican Republic, Ethiopia and Indonesia as case studies.

Figure 1: Visualisation of the affordability gap as a function of money spent per person per day and the percentiles of the survey population.

The FNG used local prices and food availability data to estimate the lowest cost of a nutrient-adequate diet. This was then compared with food expenditure data to estimate how many households are spending less than the amount needed to fulfil nutrient requirements. The authors call this the rate of non-affordability of a nutrient-adequate diet. The authors, however, note that this rate does not provide information on the magnitude of the affordability gap. In other words, it lacks insight on how large the affordability gap is, only indicating the number of households spending less than the minimum amount required to meet nutrient requirements. The authors of this paper seek to improve the FNG with what they call the nutrient-adequate diet affordability gap.

For the three case study countries, the researchers found that the Dominican Republic had the highest per capita cost of the nutrient-adequate diet followed by Ethiopia and Indonesia. For all three, the nutrient-adequate diet cost was higher than the national poverty line, indicating that meeting nutrient requirements is more expensive than basic food needs combined with non-food needs. Ethiopia had the largest total affordability gap.

The authors explore possible solutions to closing the affordability gap. They claim the issue requires both supply and demand side interventions that are contextually relevant, as the affordability gap can shift both from changes in the cost of nutrient-adequate diets (supply) and in food expenditure patterns (demand). The authors suggest fortification of regionally common foods as a supply side intervention to close the gap. They do note, however, that it is likely that supply side interventions will be slow and may not reach large sections of the population. They highlight the need for social assistance programmes such as income transfers and food subsidies which are targeted at supporting people to increase food expenditure to reduce the magnitude of the affordability gap.

The authors conclude with a discussion of how to balance various interventions to close the affordability gap. They note that the gap is often too large to be closed by direct cash assistance to households alone. They call for social assistance programs to link up with, for example, health services that provide micronutrient supplementation programs. They suggest providing specialised nutrient-dense foods for the most vulnerable populations through fortification and the implementation of social assistance programs that provide food directly. These could further reduce the affordability gap.

The authors support the use of the affordability gap as an indicator for policy decisions, especially social assistance program interventions. They emphasise the need to consider nutrient-adequate diets as opposed to basic food needs and the need to estimate not only the number of households below the affordability gap but also the magnitude, or the degree to which households fall below the affordability gap line.