Hunger and food insecurity in Nairobi's slums: an assessment using IRT models

Although linked to poverty as conditions reflecting inadequate access to resources to obtain food, issues such as hunger and food insecurity have seldom been recognized as important in urban settings. Overall, little is known about the prevalence and magnitude of hunger and food insecurity in most cities. Yet, in sub-Saharan Africa where the majority of urban dwellers live on less than one dollar a day, it is obvious that a large proportion of the urban population must be satisfied with just one meal a day. This paper suggests using the one- and two-parameter item response theory models to infer a reliable and valid measure of hunger and food insecurity relevant to low-income urban settings, drawing evidence from the Nairobi Urban Health and Demographic Surveillance System. The reliability and accuracy of the items are tested using both the Mokken scale analysis and the Cronbach test. The validity of the inferred household food insecurity measure is assessed by examining how it is associated with households' economic status. Results show that food insecurity is pervasive amongst slum dwellers in Nairobi. Only one household in five is food-secure, and nearly half of all households are categorized as "food-insecure with both adult and child hunger." Moreover, in line with what is known about household allocation of resources, evidence indicates that parents often forego food in order to prioritize their children.