This may explain the apparent high correlation between the share of food expenditure and the proportion of the undernourished population in the region. Furthermore, most efforts to effectively address the underlying causes of vulnerability that regularly threaten the lives of millions in crisis situations have not been successful. Indeed, recurring crises in the Horn of Africa, the Sahel and parts of Asia over the last few decades have demonstrated the ineffectiveness of large-scale emergency interventions to improve regional or local resilience to withstand future shocks and stresses. Panel-type data represent the ideal source (for example, data provided through the living standards measurement study) where they are available.