What's in a line?: Is partition a solution to civil war?

International Security

Volumn 34, Issue 2, 2009, Pages 82-118

  Sambanis, Nicholas ^a   Schulhofer Wohl, Jonah ^b  

^a YALE UNIVERSITY   (United States)

^b Department of Political Science ^*  (United States)

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[No Author keywords available]

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EID: 77349086148     PISSN: 01622889     EISSN: 15314804     Source Type: Journal    
DOI: 10.1162/isec.2009.34.2.82     Document Type: Article

References (128)

1. On why the internal violence in Iraq qualifies as a civil war, see Nicholas Sambanis, "It's Official: There Is Now a Civil War in Iraq," New York Times, July 23, 2006
2. On partition as a way to end that violence, see Edward P. Joseph and Michael E. O'Hanlon, "The Case for Soft Partition in Iraq," Brookings Analysis Paper, No. 12 (Washington, D.C.: Saban Center for Middle East Policy, Brookings Institution, June 2007)
3. Chaim Kaufmann, "Living Together after Ethnic Killing: In Theory, in History, and in Iraq Today," in Mia Bloom and Roy Licklider, eds., Living Together after Ethnic Killing: Exploring the Chaim Kaufmann Argument (London: Routledge, 2006), pp. 277-320
4. Ivan Eland, Partitioning for Peace: An Exit Strategy for Iraq (Oakland, Calif.: Independent Institute, 2009).
5. The most prominent argument is Chaim Kaufmann, "Possible and Impossible Solutions to Ethnic Conflict," International Security, Vol. 20, No. 4 (Spring 1996), pp. 136-175
6. Chaim Kaufmann, "When All Else Fails: Ethnic Population Transfers and Partitions in the Twentieth Century," International Security, Vol. 23, No. 2 (Fall 1998), pp. 129-156.
7. Nicholas Sambanis, "Partition as a Solution to Ethnic War: An Empirical Critique of the Theoretical Literature," World Politics, Vol. 52, No. 4 (July 2000), pp. 437-483.
8. Thomas Chapman and Philip G. Roeder, "Partition as a Solution to Wars of Nationalism: The Importance of Institutions," American Political Science Review, Vol. 101, No. 4 (November 2007), pp. 677-691.
9. Kaufmann, "Possible and Impossible Solutions to Ethnic Conflict"; and Kaufmann, "When All Else Fails."
10. According to the security dilemma argument, partition will have a pacifying effect only if populations are nearly entirely separated within a new set of borders, but sovereignty is not necessary
11. See Kaufmann, "Possible and Impossible Solutions to Ethnic Conflict," pp. 161-162.
12. In later arguments, Kaufmann joins Alexander B. Downes to argue that the new borders must be accorded legal sovereignty. See Kaufmann, "Living Together after Ethnic Killing"
13. Alexander B. Downes, "The Problem with Negotiated Settlements to Ethnic Civil Wars," Security Studies, Vol. 13, No. 4 (Summer 2004), pp. 230-279.
14. After a bloody civil war, East Pakistan seceded from Pakistan and became Bangladesh in 1971; in June 1991 Croatia declared independence from Yugoslavia and was officially recognized by the United Nations in the spring of 1992; and following the overthrow of the Ethiopian government in 1991 after a decade and a half of civil war, Eritrea's demands for a referendum on independence were granted, with Eritrea becoming independent in May 1993. In other cases of separation, however, international recognition was not achieved: the 1983 declaration of the formation of the Turkish Republic of Northern Cyprus, following the Turkish invasion that resulted in occupation of about 40 percent of the territory of the island of Cyprus, has not yet been internationally recognized. Similarly, although both Abkhazia and South Ossetia declared their independence from Georgia following their secession and brief civil wars in the early 1990s, they too failed to achieve international juridical recognition.
15. Because we want to examine the relationship between partitions and war recurrence, and be cause peaceful partitions do not create the same risks and tensions that violent partitions do, we exclude all peaceful partitions, such as the creation of the Former Yugoslav Republic of Macedonia in 1992, Czechoslovakia in 1993, and Singapore in 1965
16. Croatia became a member state of the United Nations on May 22, 1992. See United Nations General Assembly, "Admission of the Republic of Croatia to membership in the United Nations," A/RES/46/238 (May 22, 1992).
17. The internal violence in South Africa is not recognized as a civil war in all data sets, but it meets the coding criteria for civil war that we use for the period from 1976 to 1994. Guatemala saw two periods of civil war combined with a genocide of indigenous people, from 1966 to 1972 and 1978 to 1994 (or 1997, by some accounts). Tigreans challenged the Amharan-dominated Ethiopian state in a fight over control of the government from 1978 to 1991 and that war overlapped with a longer secessionist war between Eritreans and the Ethiopian state.
18. Alexander B. Downes, "The Holy Land Divided: Defending Partition as a Solution to Ethnic Wars," Security Studies, Vol. 10, No. 4 (Summer 2001), pp. 58-116.
19. Carter Johnson, "Partitioning to Peace: Sovereignty, Demography, and Ethnic Civil Wars," International Security, Vol. 32, No. 4 (Spring 2008), pp. 140-170.
20. Chapman and Roeder, "Partition as a Solution to Wars of Nationalism."
21. Sambanis, "Partition as a Solution to Ethnic War."
22. We eschew discussion of other outcomes, such as postwar democratization or economic recovery following partition. In the aftermath of civil war, we often see both democratization and higher economic growth. The causes are unclear and require new theorizing that would shift the discus sion away from an assessment of the pacification effect of partition. Sambanis discusses some evidence for a democratizing effect of partition but notes that the association is unclear because democracy data are not available for de facto partitioned regions. Chapman and Roeder use "time to democratization" as an outcome, but this is an ambiguous concept. See Sambanis, "Partition as a Solution to Ethnic War"
23. Chapman and Roeder, "Partition as a Solution to Wars of Nationalism." Rapid democratization in countries with weak institutions and no prewar experience with democracy might not be a positive outcome and could increase the risk of a return to war. For a recent argument, see Edward D. Mansfield and Jack Snyder, Electing to Fight: Why Emerging Democracies Go to War (Cambridge, Mass.: MIT Press, 2005).
24. Chapman and Roeder, "Partition as a Solution to Wars of Nationalism." The cases on their list are the partitions of Eritrea from Ethiopia, Pakistan from India, Bangladesh from Pakistan, Namibia from South Africa, Israel from Palestine, and Bosnia and Croatia from Yugoslavia. By contrast, the original data set compiled by Sambanis has 21 "civil war related" partitions out of 125 cases of civil war combining de jure and de facto partitions as well as cases where partition happens during or at the start of the war. See Sambanis, "Partition as a Solution to EthnicWar."
25. Chapman and Roeder, "Partition as a Solution to Wars of Nationalism," p. 883.
26. Survival of the peace is a binary variable coded 1 if there was no further conflict reescalation and 0 otherwise. Extent of the peace is coded 0 if there was a return to war, 1 if there was some residual violence but no war, and 2 if there was no residual violence.
27. The p-value for a t-test of equality of coefficients for partition and de facto separations is 0.07; and it is 0.11 for the coefficients of separation and autonomy.
28. Chapman and Roeder, "Partition as a Solution to Wars of Nationalism," p. 679.
29. Sambanis, "Partition as a Solution to Ethnic War."
30. For example, Burma in 1968 (Communist Party Rebellion), Algeria in 1992, Somalia in 1988, and Nigeria in 1980 (Maitatsine rebellion) are usually not thought of as nationalist wars, but they are included in Chapman and Roeder's analysis. Moreover, it is often unclear which wars are ethnic. Sambanis's list was based on ethnic war classifications in the State Failure Task Force.
31. See Daniel C. Esty, Jack A. Goldstone, Ted Robert Gurr, Barbara Harff, Marc Levy, Geoffrey D. Dabelkko, Pamela T. Surko, and Alan N. Unger, State Failure Task Force Report: Phase II Findings (McLean, Va.: Science Applications International Corporation, July 31, 1998). To check robustness, we recoded all cases using a clearer coding rule and detailed explanations of coding. Wars are classified as ethnic if the majority of the parties recruit members within a single ethnic group or if they form alliances only within that group, or along a single cleavage dimension that excludes parties fighting on the opposite side. We use this alternative list for robustness tests but preserve Chapman and Roeder's list of ethnic wars in our reanalysis of their data.
32. We define self-determination broadly and include wars that appear to be more about regional autonomy and less about secession (e.g., the Sikh rebellion in India and the Baganda rebellion in Uganda). Moreover, out of the 58 secessionist wars that we have coded since 1945 (including ongoing wars), 22 could be considered nonethnic and these would be excluded if the effects of partition are only assessed on the category of ethnic wars.
33. These results retain residual violence as the dependent variable. Amodel of war recurrence estimated on separatist wars shows partition not statistically significant and regional autonomy now predicts success (peace) perfectly (results not shown).
34. A number of other ad hoc coding changes by Chapman and Roeder influence the results but are not discussed here. Notably, Chapman and Roeder drop some ethnic wars from Sambanis's data set (such as the war between the Turkish state and the Kurds and the Philippines against the Moro Islamic Liberation Front), though these should be included according to their coding rules.
35. Historical details to support our coding are discussed in the supplement, pp. 5-7.
36. The coefficient drops from 3.29 (1.29) to 1.63 (1.03). See the supplement, p. 52.
37. Alan Hanson, "Croatian Independence from Yugoslavia, 1991-1992," in Melanie C. Greenberg, John H. Barton, and Margaret E. McGuinness, eds., Words over War: Mediation and Arbitration to Prevent Deadly Conflict (Lanham, Md.: Rowman and Littlefield, 2000), pp. 76-108.
38. United Press International, "Iceland Recognizes Slovenia, Croatia," December 20, 1991
39. Nada Buric, "Germany Recognizes Slovenia and Croatia," Associated Press, December 23, 1991
40. Germany established formal ties with Croatia on January 15, 1992, but in a letter to Croatian President Tudjman on December 23, 1991, it granted official recognition. Additionally, Estonia, Latvia, and Lithuania had already recognized Croatia.
41. United Nations General Assembly, "Admission of the Republic of Croatia to Membership in the United Nations," 86th Plenary Meeting (A/RES/46/238), May 22, 1992
42. Norman Cigar, "Croatia's War of Independence: The Parameters of War Termination," Journal of Slavic Military Studies, Vol. 10, No. 2 (June 1997), p. 34.
43. John F. Burns, "Croats Return to Stronghold on Adriatic," New York Times, December 10, 1992.
44. Nicholas Sambanis, "What Is Civil War? Conceptual and Empirical Complexities of an Operational Definition," Journal of Conflict Resolution, Vol. 48, No. 6 (December 2004), p. 830.
45. The change in government criterion is important to highlight because of other authors' coding of the wars in Croatia. Johnson, for example, does not count a partition of Croatia in 1992 "because of the difficulty of categorizing it as a war end." See Johnson, "Partitioning to Peace," p. 155.
46. In other respects, however, he uses the original data set compiled by Sambanis that counts that partition. In support of his recoding decision, Johnson notes ongoing hostilities between "Yugoslavian/Serb and Croatian forces" including "the Serb siege of Dubrovnik and the Croat siege of Bihac," and fighting between the Croatian army and the army of the Republic of Serbian Krajina, giving the examples of operations in Maslenica and Zadar in January 1993 and in the Medak Pocket in September 1993, as well as the Croatian army's Operation Flash in May 1995. Of the fighting that took place during this period, only fighting between the VSK and the Croatian army can reasonably be considered to represent a possible continuation of the 1991 war. The international recognition of the Croatian government represents an end to the war of secession. If casualty thresholds were met in the fighting between the JNA and the Croatian army after this point, we might code this as a new war. It would qualify as an international war, however, rather than as an internal one (the International Criminal Tribunal for the Former Yugoslavia considered the war after October 8, 1991, to be an international conflict, even before the distinction we are making about the international recognition of the Croatian government).
47. Quoted in Mile Bjelajac and Ozren Žunec, "The War in Croatia, 1991-1995," Scholar's Initiative Round Table Report: The Hague: Institute for Historical Justice and Reconciliation (October 20, 2007), p. 13.
48. It is also unclear whether the fighting between the JNA and the Croatian army following Croatia's recognition can be considered a war in its own right in terms of casualty thresholds. The siege of Dubrovnik, for example, is particularly well documented, following an extensive field study by the United Nations. According to the UN, "Possibly as many as 88 civilians were killed between September 1991 and the end of December 1992." Most of the civilian casualties occurred in the fall of 1991, with approximately 20 between December 1991 and 1992.
49. See United Nations, "Annex XI.A: The Battle of Dubrovnik and the Law of Armed Conflict," in S/1994/674/Add.2, December 28, 1994
50. United Nations Security Council, Final Report of the United Nations Commission of Experts Established Pursuant to Security Council Resolution 780 (1992). Local officials are quoted in a journalistic account as estimating 180 combined military and civilian casualties for the duration of the siege.
51. See Adam LeBor and Michael Evans, "Yugoslav Commander Threatens to Halt CroatianWithdrawal," Times, October 20, 1992
52. The later engagements quoted by Johnson, "Partitioning to Peace," were between the Croatian army and the VSK, as discussed above. Again, because of the victory of the Croatian government in its secession from Yugoslavia, these cannot be considered part of an ongoing war from 1991. The fighting in Bihac cited by Johnson did not even take place on the territory of Croatia, but was part of Croatia's participation in the war in Bosnia and Herzegovina. Furthermore, any assistance that the JNA gave the VSK during the period does not imply that the war at this point was not intra-state, setting aside the criterion of a change in government.
53. See Milan Vego, "The Army of Serbian Krajina," Jane's Intelligence Review, Vol. 5, No. 10 (October 1993), p. 493
54. Norman Cigar, "The Serb Guerrilla Option and the Yugoslav Wars: Assessing the Threat and Crafting Foreign Policy," Journal of Slavic Military Studies, Vol. 17, No. 3 (September 2004), p. 513.
55. See coding notes from Sambanis, "What Is Civil War?" pp. 814-858, for details on the coding of start and end dates for this conflict.
56. See also Martin Špegelj, "The First Phase, 1990-1992: The JNA Prepares for Aggression and Croatia for Defence," in Branka Magaš and Ivo Zanic, eds., The War in Croatia and Bosnia-Herzegovina 1991-1995 (London: Routledge, 2001), pp. 14-40.
57. "Operation Storm" of August 1995, in which Croatian troops invaded Krajina, was the largest land offensive in Europe since the conclusion of World War II
58. If a line of partition is established in one war and the line is redrawn in a new war, both cases could be coded (as in Cyprus, where the 1964-67 partition line was redrawn and expanded following the 1974 invasion). In India/Kashmir, by contrast, the second Kashmir war should not be coded as a case of new partition. In a version of the partition variable that identifies all partitioned countries regardless of when the civil war-related partition took place after the end of the war, these cases could be included.
59. Barry R. Posen, "The Security Dilemma and Ethnic Conflict," Survival, Vol. 35, No. 1 (Spring 1993), pp. 27-47.
60. Among those who use the logic of the security dilemma to support pro-partition arguments, see Kaufmann, "Possible and Impossible Solutions to Ethnic Conflict"; Downes, "The Holy Land Divided"; Johnson "Partitioning to Peace"
61. Erik Melander, "The Geography of Fear: Regional Ethnic Diversity, the Security Dilemma and Ethnic War," European Journal of International Relations, Vol. 15, No. 1 (March 2009), pp. 95-124.
62. Because in ethnic conflict military technology is fairly rudimentary, it is group cohesion and solidarity that underlies the offensive advantage. It also stems from the difficulty of defending against attacks on civilians, who are particularly vulnerable when they are a small fraction of the population and are geographically isolated.
63. Posen, "The Security Dilemma and Ethnic Conflict," p. 108.
64. Johnson, "Partitioning to Peace," p. 158.
65. Michael W. Doyle and Nicholas Sambanis, Making War and Building Peace: United Nations Peace Operations (Princeton, N.J.: Princeton University Press, 2006), pp. 257-280.
66. On the history of the Cyprus conflict from 1964 to 1974, see Polyvios G. Polyviou, Cyprus: Conflict and Negotiation, 1960-1980 (London: Duckworth, 1980)
67. Michael E. Dekleris, Kypriako, 1972-1974: E teleftea efkeria [Cyprus problem, 1972-1974: The last opportunity] (Athens: Ekdotiki Estia, 1981)
68. Nikos Kranidiotes, Anochyrote Politeia: Kypros, 1960-1974 [Indefensible state: Cyprus, 1960-1974], vols. 1-2 (Athens: Estia, 1985)
69. Glafcos Clerides, My Deposition, vols. 1-4 (Nicosia: Aletheia, 1989-92).
70. Robert Powell, "War as a Commitment Problem," International Organization, Vol. 60, No. 1 (January 2006), pp. 169-203.
71. For an example from the Greek civil war, see Stathis N. Kalyvas, The Logic of Violence in Civil War (Cambridge: Cambridge University Press, 2006), who establishes that there was nearcomplete knowledge of individual political allegiances at the village level such that switching sides was not feasible.
72. Chapman and Roeder, "Partition as a Solution to Wars of Nationalism," p. 679.
73. The Irish Civil War (1922-23) followed the conclusion of a 1921 treaty establishing Ireland as an autonomous unit with self-government within the British Empire. Proponents of the treaty fought advocates of complete independence. See Joseph M. Curran, The Birth of the Irish Free State, 1921-1923 (Tuscaloosa: University of Alabama Press, 1980)
74. Bill Kissane, The Politics of the Irish Civil War (Oxford: Oxford University Press, 2005)
75. After partitioning of territory (and internal war between Kenyans and the British), ethnic Somalis in Kenya tried to secede to rejoin a "greater Somalia" in the Shifta War of 1963-67. The help that Somalia gave the rebels shows how these new conflicts can develop along several dimensions, because it led to tension between Somalia and Kenya.
76. See Saadia Touval, "The Organization of African Unity and African Borders," International Organization, Vol. 21, No. 1 (December 1967), pp. 102-127
77. Richard Hogg, "Pastoralism and Impoverishment: The Case of the Isiolo Boran of Northern Kenya," Disasters, Vol. 4, No. 3 (September 1980), pp. 299-310.
78. Another example, but of the nonethnic variety, are the Yosu and Cheju-do rebellions in South Korea (1948-49)
79. See Stanley Sandler, The Korean War: No Victors, No Vanquished (London: University College London Press, 1999)
80. Allan R. Millet, The War for Korea, 1945-1950: A House Burning (Lawrence: University Press of Kansas, 2005).
81. An example is the war between Ethiopia and Eritrea five years after their partition
82. Nationalist backlash resulting from territorial loss has led to abrupt regime change. In Argentina, the junta fell after the Falklands war, as did the junta in Greece after the partition of Cyprus, and the military government of President Yahya Khan of Pakistan after the secession of East Pakistan.
83. Following the partition of India, tribal conflicts intensified with the influx of refugees, who displaced tribal people from their ancestral lands. The Nagas rebellion in 1956 is directly related to the 1947 partition, and insurgency in Tripura was triggered by the influx of Bengali refugees from what became East Pakistan following the 1947 partition and during East Pakistan's secession from Pakistan in 1971. Similarly, the Assamese insurgency resulted from rapid changes in the demographic balance between Bengalis and the outnumbered Assamese.
84. See B.G. Verghese, India's Northeast Resurgent: Ethnicity, Insurgency, Governance, Development (New Delhi: Konark, 1997)
85. Subir Bhaumik, "Negotiating Access: Northeast India," Refugee Survey Quarterly, Vol. 19, No. 2 (2000), pp. 142-158
86. Subir Bhaumik, "Insurgencies in India's Northeast: Conflict, Co-option, and Change," EWCW Working Papers, No. 10 (Washington, D.C: East-West Center Washington, July 2007)
87. Parkash Singh, "Demographic Movements: The Threat to India's Economy and Security," Low Intensity Conflict and Law Enforcement, Vol. 11, No. 1 (Spring 2002), pp. 94-115.
88. The Turkish Republic of Northern Cyprus is an example. Charles King also describes how Nagorno-Karabakh, Transnistria, Abkhazia, and South Ossetia "act in the international arena as if they were independent entities and cooperate with one another to a great degree," with this cooperation extending to security matters and pursuit of common stances in diplomatic relations with states.
89. See King, "The Benefits of Ethnic War: Understanding Eurasia's Unrecognized States," World Politics, Vol. 53, No. 4 (July 2001), p. 542.
90. For a cogent discussion of the differences between the de facto exercise of state power and the juridical notion of the sovereign state, see Robert H. Jackson and Carl G. Rosberg, "Why Africa'sWeak States Persist: The Empirical and the Juridical in Statehood," World Politics, Vol. 35, No. 1 (October 1982), pp. 1-24.
91. We use the list of civil wars from Sambanis, "What Is Civil War?"
92. For robustness tests in the supplement, see pp. 19-35.
93. We use data sets from James D. Fearon, "Why Do Some Civil Wars Last So Much Longer than Others?" Journal of Peace Research, Vol. 41, No. 3 (May 2004), pp. 275-301
94. Barbara F. Walter, "Does Conflict Beget Conflict? Explaining Recurring Civil War," Journal of Peace Research, Vol. 41, No. 3 (May 2004), pp. 371-388.
95. See http://dictionary.reference.com/browse/recurrence.
96. Walter, "Does Conflict Beget Conflict?"
97. For example, the Bangladeshi secession from Pakistan in 1971 is typically considered separate from the war in Baluchistan that started in 1973. But both the Baluchi claims and the Pakistani military's response may have been intensified by the Bangladeshi secession.
98. If a war ends in rebel victory but violence erupts immediately between the rebels and new groups that are threatened by this outcome, most data sets would not code the start of a new civil war but would lump it with the previous one
99. The supplement also contains results from robustness checks of the warnov2_01 regressions contained in table 3. See pp. 62, 67-68, 71-72, 75, 78, 80-82.
100. Lotta Harbom and Peter Wallensteen, "Armed Conflict, 1989-2006," Journal of Peace Research, Vol. 44, No. 5 (September 2007), pp. 623-634
101. Nils Petter Gleditsch, Peter Wallensteen, Mikael Eriksson, Margareta Sollenberg, and Håvard Strand, "Armed Conflict 1946-2001: A New Dataset," Journal of Peace Research, Vol. 39, No. 5 (September 2002), pp. 615-637.
102. Doyle and Sambanis, Making War and Building Peace
103. Our replication folder includes commands for simple Pearson correlation statistics between different outcomes and all versions of the partition variable for both ethnic and all wars as well as different coding of ethnic wars
104. Using a different list of civil wars, we see a negative and significant result for the effect of partition on war recurrence. See the supplement, pp. 32-35.
105. The "hardening" argument would not apply if ethnic fractionalization also increased the initial risk of civil war-not just war recurrence, which is a result found by Håvard Hegre and Nicholas Sambanis, "Sensitivity Analysis of Empirical Results on Civil War Onset," Journal of Conflict Resolution, Vol. 50, No. 4 (August 2006), pp. 508-535.
106. Different heterogeneity and polarization measures have been shown to correlate with civil war. See David Siroky, "Heterogeneity, Secession, and Violent Conflict," unpublished paper, Duke University, 2008, for an insightful analysis and a new measure of heterogeneity.
107. James D. Fearon, "Ethnic and Cultural Diversity by Country," Journal of Economic Growth, Vol. 8, No. 2 (June 2003), pp. 195-222.
108. Using ethnic fractionalization data from Alberto Alesina, Arnaud Devleeschauwer, William Easterly, Sergio Kurlat, and Romain Wacziarg, "Fractionalization," Journal of Economic Growth, Vol. 8, No. 2 (June 2003), pp. 155-194
109. ij being the share of group i (i=1 ... N) in that country.
110. For a unified South Africa, we make a composite from the ethnic group data for both countries (for South Africa in 1998 and Namibia in 1995) contained in ibid. and use total population data for each country found in the U.S. Department of State Country Background notes for the relevant year. Fractionalization for the composite unified South Africa is 0.7701, while fractionalization in postpartition South Africa and Namibia is 0.7517 and 0.6333, respectively.
111. For pre-partition Ethiopia, we take ethnic fractionalization data from Alesina et al., 0.7235 in 1983. The authors also provide postpartition fractionalization for Eritrea, as 0.6524 in 1998. We calculate the postpartition ethnic fractionalization of Ethiopia as 0.7974 in 1994, using group shares of the population from the 1994 Ethiopian Census, taking all ethnic groups having at least 2.4 percent of the population (because in the data for pre-partition Ethiopia, the smallest group-share of the population for the groups included is 2.4 percent). Given that our pre-partition fractionalization data are ten years prior to partition, we cannot say with certainty that ethnic fractionalization in Ethiopia increased following partition. At a minimum, however, it is highly unlikely that it decreased with partition. Additional details available from the authors upon request.
112. Polarization data are taken from José G. Montalvo and Marta Reynal-Querol, "Ethnic Polarization, Potential Conflict, and Civil Wars," American Economic Review, Vol. 95, No. 3 (June 2005), pp. 796-816.
113. 2 distribution, so some of our inferences may be mistaken. We can check this with bootstrapping-a nonparametric method of making inferences about population parameters based on estimates of a statistic's sampling distribution. The sampling distribution is obtained by resampling the data with replacement many times (we use 1,000 repetitions), thus treating the observed data as if it were the population. Thus, the bootstrap depends critically on the assumption that the observed distribution is a good approximation of the population distribution.We then use that distribution to estimate the standard error of the statistic of interest (the coefficient for the explanatory variables in our model) and to obtain confidence intervals.
114. Readers might object that the effects of partition should be compared only to cases of powersharing because military victories are thought to be more stable than other war outcomes and they may well be more repressive (hence even if there is no further civil war, human welfare may be lower after a victory). Victories, however, are not necessarily more stable after negotiated settlements (see Doyle and Sambanis, Making War and Building Peace), and partitions are a type of victory by the rebels. We nonetheless drop cases of government victory as a robustness test (supplement, pp. 76-78).
115. We drop coups, genocides, and geographical regions one at a time, as well as all but the first observation for each country unless civil wars in the same country are too far apart or are clearly independent. See the supplement, pp. 76-83.
116. We prefer the short-term outcomes for reasons explained in the supplement. See results from the duration analysis in the the supplement, pp. 116-120. Survival analysis can be used to examine the duration of the peace beyond the two-year mark and accounts for right-censoring, offering an estimate of the risk of peace failure at time t given that failure has not occurred until then. The dependent variable is now "time until peace failure," a continuous variable that measures peace duration in months from the end of the war until the peace fails or until analysis time ends.
117. All parametric models select (by assumption) a functional form to optimize the model's fit to the observed data. The models that we have estimated thus far rely on an assumption of linearity in the latent variables. Yet, some of the explanatory variables in the model are correlated and the effects of partition may differ in different ranges of some covariates. Due to the small number of partitions, we do not show results from regression models with interactive effects. Model fit statistics show more support for models without interactions (see the supplement, pp. 89-96).
118. We use matching to deal with the potential selection of partition on observables (i.e., the set of covariates included in the model). Matching relies on the assumption of no omitted variable bias.
119. Jasjeet S. Sekhon, "Multivariate and Propensity Score Matching Software with Automated Balance Optimization: The Matching Package for R," Journal of Statistical Software (forthcoming).
120. Detailed estimates and balance statistics are reported in the supplement, pp. 106-109.
121. Donald B. Rubin, "Bayesian Inference for Causal Effects: The Role of Randomization," Annals of Statistics, Vol. 6, No. 1 (January 1978), pp. 34-58.
122. In other words, we assume that treatment values are stable for each country-war-there is an outcome under partition and an outcome under no partition-and these treatment values are invariant to whether partition occurred after other country-wars
123. A SUTVA violation might occur if two countries, A and B, are partitioned, and civil war recurs in country A and that war spreads to country B, leading to renewed war in B. A different selection problem might arise because some cases enter the sample only after certain outcomes, such as a failed partition that results in war. We deal with this in the supplement by dropping all but the first civil war in each country and the results are qualitatively the same for two-year and five-year outcomes even though we end up with only ninty-two cases (see the supplement, pp. 82-83).
124. The only study to date that has tried to model the possible endogeneity of partitions by estimating an instrumental variables model of war recurrence is Sambanis, "Partition as a Solution to Ethnic War." The instruments used in that study, however, are unlikely to satisfy the exclusion restriction.
125. N. Gregory Mankiw, "The Growth of Nations," Brookings Papers on Economic Activity, Vol. 1, No. 1 (1995), pp. 275-326
126. Thad Dunning, "Model Specification in Instrumental-Variables Regression," Political Analysis Vol. 16, No. 3 (Summer 2008), pp. 290-302.
127. James D. Fearon, "Separatist Wars, Partition, and World Order," Security Studies, Vol. 13, No. 4 (July 2004), pp. 394-415.
128. Following a career of conflict generation and conflict resolution, however, Henry Kissinger warned that "above all, one has to understand that almost no problem has [a] final solution. In diplomacy, every so-called solution is an admissions ticket to another set of problems." Quoted in Isaac Arnsdorf, "Kissinger Speaks on U.S. Policy in M. East," Yale Daily News, December 7, 2007, http://www.yaledailynews.com/articles/view/22748.