African Union defense demand and spatial spillovers

The study of the determinants of African defense demand is of enhanced importance because of unique security challenges, growing defense spending, and changing African Union (AU) integration. From a political geographical vantage, this study presents the first analysis of AU members' demand for defense spending, which accounts not only for members' relative locations, but also for political considerations (e.g., state failure, coups, and armed conflicts). Our analysis marries the economics of alliances with spatial considerations that include members' contiguity, between-member distance, and contiguous threats. Given two-way causal concerns, we employ an appropriate defense demand estimator (i.e., two-step generalized method of moments) correcting for the endogeneity between a member's defense spending and that of the other allies. Evidence of defense free riding or relying on the defense spending of other AU members characterizes contiguous and nearby AU countries during 2002–2019. Defense spending is an income normal good, which generally increases with armed conflict. UN and non-UN peacekeeping troop contributions provide some free-riding opportunities within the AU. Given regional differences in armed conflicts and coups, the determinants of African defense demand are influenced by regional divisions.