Nunn and Qian (2014) examine the effect of US food aid on conflict in recipient countries. They find that US food aid increases the incidence and duration of civil conflicts but has no significant effect on interstate conflicts or the onset of civil conflicts. The effects are most pronounced in countries with a recent history of civil conflict. The study uses two sources of variation: time variation in US wheat production and cross-sectional variation in a country's likelihood of receiving US food aid. They construct an instrument based on the interaction of last year's US wheat production and the frequency of receiving US food aid. The 2SLS estimates show a large, positive, and statistically significant effect of US food aid on the incidence of civil conflict, but no effect on interstate conflict. The study also finds that food aid has little effect on the onset of conflicts but significantly increases their duration. The findings suggest that the primary effect of food aid is to prolong the duration of smaller-scale civil conflicts. The study contributes to the literature on the effects of foreign aid and conflict determinants. The results imply that US food aid may exacerbate civil conflicts, particularly in countries with a history of conflict. The study highlights the challenges of humanitarian aid in conflict-prone regions, where aid can be stolen or misused, fueling conflict. The findings have important implications for aid policy and the design of humanitarian assistance programs.Nunn and Qian (2014) examine the effect of US food aid on conflict in recipient countries. They find that US food aid increases the incidence and duration of civil conflicts but has no significant effect on interstate conflicts or the onset of civil conflicts. The effects are most pronounced in countries with a recent history of civil conflict. The study uses two sources of variation: time variation in US wheat production and cross-sectional variation in a country's likelihood of receiving US food aid. They construct an instrument based on the interaction of last year's US wheat production and the frequency of receiving US food aid. The 2SLS estimates show a large, positive, and statistically significant effect of US food aid on the incidence of civil conflict, but no effect on interstate conflict. The study also finds that food aid has little effect on the onset of conflicts but significantly increases their duration. The findings suggest that the primary effect of food aid is to prolong the duration of smaller-scale civil conflicts. The study contributes to the literature on the effects of foreign aid and conflict determinants. The results imply that US food aid may exacerbate civil conflicts, particularly in countries with a history of conflict. The study highlights the challenges of humanitarian aid in conflict-prone regions, where aid can be stolen or misused, fueling conflict. The findings have important implications for aid policy and the design of humanitarian assistance programs.