of the UN Observer Group in Central America (ONUCA) in 1989. Since then, DDR has figured prominently as part of UN operations in El Salvador, Cambodia, Mozambique, Angola, Liberia, Sierra Leone, Guatemala, Tajikistan, and Burundi to name a few. By 2000, when the secretary general was asked to report to the Security Council on the role of the DDR efforts, he felt confident enough to con- clude that ������a process of disarmament, demobilization, and reintegration has repeat- edly proved to be vital to stability in a post-conflict situation������ (United Nations 2000, 1 italics added). But despite the confidence of policy makers in the impact of DDR programs, there have been few systematic efforts to evaluate the determinants of successful reintegration by ex-combatants after conflict. The literature is chock-full of ������lessons-learned������ assessments that attempt to parse the factors that account for the success (or failure) of a given DDR program (World Bank 1993).1 Surprisingly, this debate has typically been carried out without an appropriate source of variation in the key explanatory variables. At the macro level, studies of DDR have typically not engaged in a comparison of outcomes in countries that did and those that did not receive interventions. At the micro level, strikingly few rigorous attempts have been made to identify factors that might explain why some individuals and not others are able to successfully reintegrate after conflict. In particular, no studies have systematically compared the reintegration success of those that have and have not participated in demobilization and reintegration programs. In practice, identifying the effects of DDR programs on peace building is diffi- cult at the macro level. These programs rarely take place in isolation. They typi- cally are complemented by other military, social, and economic interventions. An academic consensus appears to be emerging that these multidimensional peace- keeping operations improve the prospects for peace, democracy, and improved eco- nomic performance in the aftermath of conflict (Walter 1997 Doyle and Sambanis 2000, 2006). Moreover, outside intervention seems to be particularly valuable when hostilities are deep and local capacities have been destroyed (Doyle and Sam- banis 2000, 2006). But the multidimensional character of these interventions makes Authors��� Note: This research draws on a large survey led by the authors together with the Post-conflict Reintegration Initiative for Development and Empowerment (PRIDE) in Freetown, Sierra Leone. Finan- cial support came from the Earth Institute at Columbia University and logistical support from the Demo- bilization and Reintegration office at the United Nations Mission in Sierra Leone (UNAMSIL). We are particularly grateful to Alison Giffen and Richard Haselwood for their extensive work on this project to Christina Cacioppo and Daniel Butler for research assistance to Allan Quee, Patrick Amara, and Lawr- ence Sessay, our partners in the field at PRIDE and to Desmond Molloy at UNAMSIL. We also thank Christopher Blattman, David Cunningham, James Fearon, Kristian Gleditsch, David Laitin, Andrew Mack, James Pugel, Jonah Schulhofer-Wohl, Stephen Stedman, Michael Tomz, Barbara Walter, Jonathan Wand, and participants in seminars at the University of California, San Diego Yale University and the annual meeting of the American Political Science Association. Replication materials are avail- able at http://www.columbia.edu/ ��� mh2245/papers1/jcr2007 and http://jcr.sagepub.com/cgi/content/ full/51/4/531/DC1/. 532 Journal of Conflict Resolution at YALE UNIV on February 22, 2011 jcr.sagepub.com Downloaded from

it difficult to discern the individual contribution of specific programs to overall suc- cess. There are, quite simply, too few cases and too many confounding variables. In this article, we instead turn to micro-level data, drawing on a survey of 1,043 combatants from the five warring factions in Sierra Leone���s civil war. We employ measures of variation in the reintegration experience across former combatants to answer the question, what determines the ability of ex-combatants to reintegrate into society? Our primary goal is to identify the impact of international attempts to facil- itate reintegration, but we also explore how the ability of ex-combatants to reinte- grate depends on their personal characteristics and on their experience of conflict. We address these questions using a second-best approach. We emphasize that a first-best approach exists, using a method of randomized intervention, in which (for example) the order in which individuals undergo DDR processes is partly rando- mized. This method provides enormous power for understanding the impact of external interventions, but we know of no attempt to use the principle of randomi- zation to evaluate DDR efforts in any postconflict country. In the absence of rando- mization, we use data from ex-post survey work to identify the correlates of successful reintegration and look for evidence of the impact of DDR programs. To preview our results, we find surprising heterogeneity across outcome measures. The breaking of ties between combatants and their factions, for example, is not asso- ciated with more successful reintegration into the economy, the community, or politi- cal life. Different processes appear to underlie distinct facets of social, economic, and political integration. Moreover, a number of individual-level determinants of success- ful reintegration stand out. Past participation in an abusive military faction is the strongest predictor of difficulty in achieving social reintegration. For economic and political integration, we find that individuals from wealthier and more educated back- grounds report greater difficulties. Higher ranking combatants, we find, appear to be less trusting of democratic politics. On our measure of the disestablishment of military factions, the evidence suggests that ideologues are more likely to remain connected to their units, as are male fighters and younger ex-combatants. Our examination of DDR programs produces little evidence in support of claims that these effectively break down factional structures and facilitate reintegration. Combatants not exposed to the DDR program appear to reintegrate just as success- fully as those that participated. In the absence of a randomized trial, however, there are a number of reasons why we might fail to identify effects even if they exist��� chief among these are spillover, selection, and sampling biases. We examine each of these sources of bias in turn. Based on the data available to us, our analysis sug- gests that the nonfinding cannot be easily attributed to selection or sampling effects. There is, however, some evidence for one of our four outcome measures that spillover effects may render our ability to identify program effects particularly difficult. Nonetheless, to discount this prima facie evidence that the DDR program in Sierra Leone had no impact, policy makers will need to employ more robust stra- tegies for demonstrating the efficacy of demobilization and reintegration efforts. Humphreys, Weinstein / Demobilization and Reintegration 533 at YALE UNIV on February 22, 2011 jcr.sagepub.com Downloaded from

The second section of this article situates demobilization and reintegration in the context of existing theoretical arguments about the determinants of successful peace building. We then explore the question of whether the impact of macro-level programs should be observable at the micro level, drawing out implications from our discussion that then shape our empirical strategy. A fourth section introduces the case of Sierra Leone and describes our research method. The fifth, sixth, and seventh sections describe our empirical strategy for studying the determinants of reintegration success and identifying the effects of international programs. A con- cluding section discusses the relevance of our results for broader discussions of DDR and postconflict strategy. Hypotheses on Demobilization and Reintegration Policy makers have long supported demobilization and reintegration because of the perceived impact such programs have on the risk of a return to conflict. Spear (2002) emphasizes the importance of dissolving armed factions: ������Peace requires breaking the command and control structures operating over rebel fighters . . . thus making it more difficult for them to return to organized rebellion������ (p. 141). Eco- nomic dimensions of postconflict reintegration receive priority from the Interna- tional Peace Academy (2002), which argues that ������ex-combatants must be able to earn a livelihood through legitimate means������ (p. 5). Given that a higher risk of con- flict is associated with an absence of income-earning opportunities for young men (Collier and Hoeffler 2004), risk-reducing demobilization and reintegration pro- grams seek to create economic opportunities for combatants. The United Nations (2000) points to the need to ������convert combatants who pur- sue their objectives through force to civilians who pursue their objectives through other means������ (p. 11). Generating confidence in a democratic alternative to militar- ized politics is a ������critical test of the peace process������ (United Nations 2000, 11). Finally, civil society organizations often underscore the need for reconciliation in the aftermath of conflict. To the extent that ex-combatants gain acceptance from family members, friends, and neighbors through formal or informal processes of reconciliation, communities are in a better position to reintegrate former soldiers and facilitate their reinsertion into civilian life. Policy makers thus recognize a range of distinct channels through which the successful demobilization and reintegration of ex-combatants contributes to suc- cessful peace building. The basic hypothesis we examine here is whether DDR pro- grams facilitate this demobilization and reintegration, returning the many benefits attributed to such programs by policy makers. We look for evidence that participa- tion in demobilization and reintegration programs dissolves the factional networks linking ex-combatants to one another, improves income-earning opportunities available to former fighters, generates increased confidence in the democratic pro- cess, and facilitates reconciliation with family, friends, and community members. 534 Journal of Conflict Resolution at YALE UNIV on February 22, 2011 jcr.sagepub.com Downloaded from

Our core hypothesis, though motivated by policy debates about appropriate post- conflict strategies, is consistent as well with theoretical work in the literature on civil war termination. Two underlying mechanisms can be identified that link DDR programs to the successful dissolution of warring factions in the aftermath of civil war. The first draws on the logic of the security dilemma (Walter 1997 Roe 1999). Even if all parties favor the dissolution of their military factions, in an institution- ally weak environment, mutual mistrust may result in an unwillingness to take the first step toward demobilization. By offering assurances that warring factions will be protected, terms will be fulfilled, and promises will be kept, a credible third-party guarantee provides one solution to this dilemma. By providing an environment in which formerly warring parties can learn of each other���s intentions, DDR programs can provide fighters with the security and confidence needed to disengage from their factions and return to civilian life. The second draws on research that examines the role of ������spoilers������ (Stedman 1997). Spoilers���individuals that use violence to undermine peace efforts���may seek to maintain the structures of armed factions to bargain for more favorable returns and thereby exacerbate security dilemmas. Yet as argued by Stedman, posi- tive measures may exist to address the grievances of factions that stand in the way of peace. Through the provision of training and transfers of monetary compensation, DDR programs may alter the relative benefits and costs of engagement with a peace process and remove the incentives for spoilers to maintain organizational structures. These theoretical considerations suggest individual-level features that might render reintegration more difficult in some circumstances: Hypothesis 1: Individuals that distrust the intentions of other groups should be less likely to reintegrate. Hypothesis 2: Individuals that are dissatisfied with the terms of the peace should be less likely to reintegrate. However, the theoretical logic suggests also (consistent with the perspective of pol- icy makers) that DDR programs should be effective in facilitating reintegration. Moreover, the logic suggests that these programs should be particularly salient among individuals for whom distrust and dissatisfaction would otherwise impede reintegration. This reasoning leads to the following three further hypotheses: Hypothesis 3: Participation in DDR programs will lead to more successful demobilization and reintegration among ex-combatants. Hypothesis 4: The impact of DDR programs should be most pronounced among individuals who distrust the intentions of other groups. Hypothesis 5: The impact of DDR programs should be most pronounced among individuals who are dissatisfied with the terms of the peace. Humphreys, Weinstein / Demobilization and Reintegration 535 at YALE UNIV on February 22, 2011 jcr.sagepub.com Downloaded from

Beyond these hypotheses regarding the impact of DDR programs, we also explore a series of individual- and group-level characteristics that might condi- tion successful demobilization and reintegration. These control variables are of considerable independent interest in that our study provides a first opportunity to identify some of the empirical correlates of reintegration. Recent research in social psychology and anthropology suggests some plausible determinants of reintegration success. A rich empirical literature has examined the impact on reintegration of exposure to violence on the part of noncombatants (see, for example, Dyregrov, Gjestad, and Raundalen 2002 Husain et al. 1998). Some single-country studies in Sierra Leone have examined the reintegration prospects of particular subgroups of combatants, notably youth (Richards et al. 2003) and women and girls (Mazurana et al. 2002). But beyond these studies, our review of the literature on demobilization and reintegration yields little in the way of sys- tematic theories about the conditions under which some combatants but not others will give up their arms and reintegrate into civilian life. While scholars have devoted much attention to the study of how organizations form, considerably less effort has been directed at their dissolution. Thus, given the rudimentary state of our knowledge, our examination of these factors is exploratory: we seek to docu- ment the extent to which a set of demographic and social factors can account for successful reintegration across individual combatants. In the analysis that follows, we consider, without stating explicit hypotheses, the relationship between reintegration success and eleven individual, group, and com- munity characteristics: five measures of an individual���s demographic background (age, gender, ethnicity, education, and wealth), four measures of an individual���s experience of the conflict (whether the individual was abducted, whether he or she was a political supporter of the group, whether he or she was an officer, and a mea- sure of the abusiveness of the unit in which an individual fought) and, finally, two measures of community characteristics (an indicator of wealth and an index of the degree to which the community suffered from violence during the war). Macro Processes and Micro Effects Before turning to our empirical analysis, we are confronted by an inferential challenge. In shifting from the macro to the micro, we make an implicit assumption that the impact of a DDR program in a given country can be discerned by compar- ing reintegration outcomes across individuals that did and did not participate in a program. This assumption makes sense if the macro effects of DDR programs work through the positive impact such interventions have on individual combatants, as enumerated in the previous section. To the extent that DDR is designed explicitly to break down ties within factions and facilitate economic, political, and social reintegration, these effects should, in principle, be visible at the individual level. We emphasize, however, that if DDR programs work instead at a more aggregate 536 Journal of Conflict Resolution at YALE UNIV on February 22, 2011 jcr.sagepub.com Downloaded from