Exploring good gaps for right-sizing food assistance: Methods, data challenges, and lessons learned

Accurate measurement of the depth of acute food insecurity remains a major gap in current global monitoring systems. While the Integrated Food Security Phase Classification (IPC) identifies the scale and geographic distribution of populations in crisis, it does not quantify the magnitude of food intake shortfalls faced by affected populations. This paper outlines an exploratory data exercise that tests three proxy approaches to estimating food gaps using available IPC and DIEM data. First, we derive back-of-envelope caloric deficit estimates by IPC phase using thresholds from the Household Economy Approach. Second, we assess whether widely used dietary diversity, experiential food insecurity, and coping capacity indicators can serve as proxies for calorie deficits by analyzing their cross-indicator correlations. Third, using microdata from FAO's DIEM surveys matched to IPC area phases, we estimate indicator-specific shortfalls using a Foster-Greer-Thorbecke gap framework and translate these into food assistance estimates. The results show that proxy indicators cannot be used interchangeably to estimate caloric shortfalls, reflecting weak cross-indicator correlations consistent with the existing literature. Within-phase heterogeneity is wide and data limitations are substantial. The paper documents these approaches and their limitations as an intermediate step. The paper provides several recommendations for improving data collection that would allow for more reliable food gap estimates using the framework presented in this paper, which in turn could then operationalized for humanitarian agencies to ‘right size’ and better target food assistance to populations facing acute food insecurity.