Smith 1

Christopher Smith

Dr. Michael Hogg

TNDY 402A: Extremism

13 October 2010

Systemic Causes of Violent Intra-State Conflict

1. Introduction

While the importance of social-psychological and historical studies of insurgency should

not be underestimated, one weakness of such studies is that they often lack realistic policy

implications. For this reason, the International Relations literature has typically focused on state-

or system-level causes of insurgency that governments might be able to ameliorate through

public policy. Of particular importance are a number of empirical studies have attempted to

assess the statistical significance of various variables as predictors of intra-state conflict. The

present paper tabulates and summarizes those empirical findings, then examines some of their

possible policy implications. Among other things, the findings presented here suggest that states

can enhance internal stability by promoting a pluralistic ideology, centralizing and strengthening

government, promoting economic growth, moving toward extreme democracy or autocracy,

curtailing population growth, and avoiding territorial expansion.

2. Methodological Considerations

The studies examined here fortunately use only two broad specifications of civil war,

summarized by Hegre and Sambanis (523): “[Civil war] must have caused 1,000 deaths in total

and in at least a three year period. . . . The Uppsala/PRIO [internal armed conflict] data set has an

annual twenty five battle deaths threshold and therefore is not limited to civil war.” In both cases,

one of the actors in the conflict must be the government. Table 1 shows which variables the

various studies found to be significant predictors of civil war, and Table 2 shows which variables

Smith 2

the studies found to be significant predictors of internal armed conflict (IAC). We might think of

these as the results for “large-scale” and “small-scale” conflicts, respectively, though of course

the IAC data do not exclude larger-scale outbreaks.

As for the specific variables listed in Tables 1 and 2, the various studies operationalized

them in a variety of different ways. I have taken some liberties in Tables 1 and 2 in terms of

relabeling variables in order to clarify what was measured and to provide cross-study

comparability. The studies also used a wide variety of model specifications and thresholds for

statistical significance. Unfortunately the measures of statistical significance (such as p-values

and correlation coefficients) often were not comparable across studies, so Tables 1 and 2 report

significance or non-significance as a dichotomous value for each study. A few studies used

multiple specifications, and there were variables that were significant in some specifications but

not in others. Usually I have chosen to interpret such results conservatively, and to code as

“significant” only those variables whose significance was fairly robust against specification

changes.

Finally, one should keep in mind when examining Tables 1 and 2 that not all the reported

results are of the same theoretical caliber. The study by Hegre and Sambanis is important, though

they may have set their threshold for significance too low. The studies by Benson and Kugler

and Østby are suggestive, but include too few variables to be fully definitive. The study by

Montalvo and Reynal-Querol suffers from deficient specification, as explained by Schneider and

Weisehomeier (5-7). Among the better-specified studies are those by Fearon and Laitin and

Collier and Hoeffler, though even these were insufficiently sophisticated in their

operationalization of ethnic and religious variables. Several of these variables exhibit a high

degree of endogeneity, such that including them together in the same regression model tends to

undermine their statistical significance.

Smith 3

3. Ethnic and Religious Variables

Most studies have not found ethnic or religious fractionalization variables to have a

significant effect on civil war. In part this may be because fractionalization, dominance, and

polarization variables are somewhat endogenous, so including them in the same model causes

one or more of them to lose significance (Schneider and Weisehomeier 5). Collier and Hoeffler

also include their ethnic and religious fractionalization variables in the same model as a “social”

fractionalization variable that combines the two. Under such circumstances it is hardly surprising

that the disaggregated variables fall out of the analysis (11-13). Another problem is the way that

religions have been categorized. All “Christians” and all “Muslims” are lumped together, for

example (Schneider and Weisehomeier 5-7). Yet history suggests that the most salient religious

divisions are often between sectarian groups within a single tradition, such as Shia and Sunni or

Protestants and Catholics (Wuthnow xv). The American Civil War, for example, has recently

been interpreted as a religious war between pro- and anti-slavery Protestants (Noll 43-46)—a

religious division that would not show up in the typical indices of religious fractionalization and

polarization. It may be that similar groups are perceived as a greater threat than more alien ones

because similar groups are more attractive to defectors from one’s own group.

To the extent that fractionalization is significant, it turns out to be a restraint rather than a

stimulant to war (Collier and Hoeffler 13; Fearon and Laitin 20). This is somewhat surprising to

Fearon and Laitin, who had predicted that fractionalization would increase the probability of war

(9). Collier and Hoeffler explain that rebel groups may be able to operate more effectively under

conditions of social cohesion (13). An alternative explanation is that fractionalization proxies for

the presence of a pluralistic ideology. Not only are pluralistic societies more likely to have an

open immigration policy, leading to greater fractionalization, but fractionalization itself may tend

to reinforce such a tolerant ideology. In a highly fractionalized society, people are not only more

Smith 4

likely to have their negative stereotypes of other groups challenged by direct personal encounter

(Wuthnow xvi), but they are also more likely to have to learn to cooperate with other groups in

order to establish an effective government.

Even less significant than fractionaliztion for civil war onset is ethnic or religious

polarization. (While polarization is not significant for onset, it does tend to increase duration. cf.

Schneider and Weisehomeier 13-14; Esteban and Ray 164-65). This may be because civil wars

occur only in newly-polarized countries—countries that have recently become polarized through

immigration, conversion, or demographic shifts. During the Protestant Reformation, a large

Protestant influx into the Catholic Netherlands resulted in an eighty-year war for political

dominance over the country. When it became clear that neither group would be able to achieve

hegemony, they developed a pluralistic ideology and power-sharing strategy that prevented

further conflict outbreaks (Lindberg 308). Thus polarized societies may undergo an initial period

of prolonged warfare followed by a permanent, stable, pluralistic peace. Future studies should

look specifically at polarization that has resulted from rapid changes in relative group size. It

would also be useful to interact polarization with regional separation, since both the US Civil

War and the recent Sudan conflict occurred between religious groups that were regionally

separated.

Unlike polarization and fragmentation, ethnic dominance—here meaning the presence of

one large majority ethnic group and one substantial minority ethnic group—proves to be a highly

significant stimulant to war (Collier and Hoeffler 13; Hegre and Sambanis 526). Ethnic

dominance is arguably less conducive to pluralistic ideology than either polarization or

fragmentation, because the dominant group can form an effective governing coalition without

including other groups. The Rwandan and Sudanese genocides were both carried out by majority

ethnic groups against sizable minorities. Since the Rwandan genocide was partly motivated by

Smith 5

the majority group’s resentment of the greater wealth and power of the minority group

(“Rwanda”), it might be interesting to interact ethnic dominance with socio-economic

stratification. In this vein, Østby finds that educational differences falling along specifically

ethnic lines are a statistically significant predictor of civil war (157).

The results for IAC are somewhat different from the results for civil war. Whereas

fractionalization is a mild restraint to civil war, it is a stimulant to IAC (Hegre and Sambanis,

528). Probably this is because a variety of radical ethnic groups exist on the fringes of

fractionalized societies, where they remain relatively isolated from pluralism but can still

mobilize enough resources to meet the 25 casualty requirement. In contrast to fractionalization,

dominance and polarization lose statistical significance for IAC (Hegre and Sambanis, 528).

It is also worth noting in passing that Fearon and Laitin found that Islam had no

statistically significant effect on civil war when controlling for other variables (25). Islam could

still be causing civil war indirectly, by influencing political, economic, or demographic variables,

but it does not appear to have any substantive direct effect.

The findings for ethnic and religious variables are not fully conclusive, and bear further

study. They do, however, raise a few policy possibilities for increasing long-term intrastate

stability. Firstly, socio-economic discrepancies between ethnic groups should be eliminated,

since these seem to promote ethnic conflict. Secondly, a permissive immigration policy might

reduce the probability of civil war. On the other hand, it would increase the probability of IAC.

In formulating immigration policies, countries will have to weigh the risks of fractionalization

against the potential benefits. In the meantime, a safer policy might be for government to

actively promote a pluralistic ideology. Rather than increasing the number of immigrants coming

into the country, this could be accomplished by increasing the visibility of the minority groups

Smith 6

already present: sponsoring positive media coverage of these groups and integrating them more

into the mainstream life of the society.

4. Political and Economic Variables

Some of the strongest predictors of civil war are political and economic. In the political

realm, the best predictors seem to be weak government and intermediate regime type. In the

economic realm, high GDP, growth, and development all serve as restraints to war.

Strong governments are typified by high centralization, high resource extraction from the

population, and high levels of militarization. Weak governments tend to be decentralized

confederacies of semi-autonomous regions, ineffective at collecting taxes, and incapable of

sustaining extensive military forces. Not surprisingly, centralization, militarization, and political

extraction all turn out to be statistically significant restraints to civil conflict (Hegre and

Sambanis 526, 28; Benson and Kugler 204-05). Strong governments are better able to avert

conflict before it begins. Similarly, new states and states that have undergone recent instability or

regime changes are considerably more prone to civil war (Hegre, Ellingsen, Gates, and Gleditsch

38; Fearon and Laitin 24; Hegre and Sambanis 526). This is probably because the governments

of such states have not had time to consolidate control of their countries.

Even weak states, of course, can be stabilized to some degree by the availability of

foreign military intervention. Before the fall of the Soviet Union, for example, the Warsaw Pact

nations experienced no civil war. French colonies experienced similar stability prior to the

decolonization period (Fearon and Laitin 26-27). This effect is somewhat offset, however, by a

“spillover” effect from instability in neighboring countries. States in generally unstable regions

such as the Middle East and North Africa are generally more war-prone than states in Western

Europe and the United States, even when controlling for other variables (Hegre and Sambanis

526, 32).

Smith 7

As for regime type, various measures indicate that the most stable regimes are extreme

democracies and autocracies, whereas intermediate regimes such as semi-democracies are much

more prone to civil war (Hegre, Ellingsen, Gates, and Gleditsch). Intermediate regimes may be

those that employ just enough coercion to create resentment, but not enough to effectively crush

political opposition. By contrast, extreme autocracies successfully control their populations, and

extreme democracies avoid creating resentment and provide peaceful outlets for political protest.

All well-specified studies agree that democracies are not significantly more stable than

autocracies when controlling for other variables. Democracy may act as an indirect restraint to

civil war by promoting economic prosperity, but it has no direct effect. Certain variables related

to democracy, however, bear further investigation. Reynal-Querol finds that inclusive

governments—multi-party systems that require fairly consensual and coalitional approaches to

government—are more stable than less inclusive majoritarian governments such as presidential

systems (446). This conflicts with Hegre and Sambanis’s finding that presidential systems are a

restraint to war (526), but the Hegre and Sambanis finding frankly seems anomalous. They cite

Przeworski, et al. as the source of their data for this variable, but Przeworski, et al. come to

precisely the oppositie conclusion: that parliamentary systems are much more stable than

presidential ones (134-35). Another variable that merits further study is regulation of

participation. In this context, regulation of participation means that a state has stable and

recognized political parties, with binding rules on how, when, and whether diversity of opinion

may be expressed. Unregulated participation is more subject to change over time, and has fewer

barriers to coercive strategies (“Codebook” 34). According to Hegre and Sambanis, regulation of

participation is a significant restraint to war (526).

Economic variables are also very important. High GDP per-capita, rapid GDP growth,

and high levels of industrial development and male secondary education all seem to be

Smith 8

significant restraints to civil conflict (Collier and Hoeffler 16; Hegre and Sambanis 526, 28;

Fearon and Laitin 20). One plausible interpretation of this finding, from a rational-choice

perspective, is that a combatant who dies in war during a time of prosperity loses more—has a

higher “foregone income”—than one who dies during an economic depression (Collier and

Hoeffler 16). Another possible interpretation is that these economic variables proxy for strong

government or for other conditions conducive to stability (Fearon and Laitin 3).

One economic variable that seems to act as a stimulant to war is the export of oil as a

primary commodity. Collier and Hoeffler suggest that oil exports provide an opportunity for

rebel groups to fund themselves through extortion (16), but a more likely explanation is Fearon

and Laitin’s suggestion that oil marks “relative state weakness at a given level of income” (29).

Fearon and Laitin do not, however, reject the possibility that availability of rebel funding might

predict civil war. They merely suggest that “A better measure for financing potential would focus

on the presence of minerals or contrabands that can reward control of a small enclave with huge

profits” (29-30). No such variable has yet been tested, but it is a promising suggestion. The

Taliban in Afghanistan, for example, are said to be financed partly through illicit trade in opium

(Schmitt). If the presence of illicit cash crops turns out to be significant, then legalization of the

trade in these crops might offer a route to stability. (Admittedly, legalization might need to occur

in market countries as well as in Afghanistan itself.)

Other policy implications of this analysis would seem to be fairly straightforward. The

best recipe for long-term state stability would seem to be to strengthen and centralize

government, adopt either extreme democracy or extreme autocracy, regulate political

participation, and stimulate economic growth. In light of this evidence, it seems that by creating

economically weakened semi-democracies in Iraq and Afghanistan, the United States has only

Smith 9

created the conditions for civil conflict in these countries. Their governments are likely to

survive only if propped up by foreign military support.

5. Other Variables

Besides the variables already discussed, a few other significant ones are population,

population dispersion, and the presence of mountains. One of the most consistent predictors of

civil war is population. Population has a more or less monotonic relationship with civil war,

probably simply because every additional person in a state is an additional potential rebel. A

higher population means more opportunities for rebellion (Fearon and Laitin 39; Collier and

Hoeffler 13; Hegre and Sambanis 526; Schneider and Weisehomeier 21-23). Also quite

significant is the influence of population dispersion. Collier and Hoeffler find that a highly

dispersed population is a stimulant to war, perhaps because rebels can hide in remote rural

regions of the country and gather sufficient strength to challenge government forces (5, 26).

Mountainous terrain may also provide hiding places for rebels, though the evidence for its

significance is somewhat mixed (Fearon and Laitin 39, Hegre and Sambanis 526, Collier and

Hoeffler 25, Schneider and Weisehomeier 21-23). Perhaps the partial colinearity of these two

variables accounts for the weakness of the statistical significance of the latter.

In terms of policy, these findings would seem to argue for the favorability of population

controls and non-imperialistic diplomacy. By taking measures to reduce birth rates, states can

eliminate the added risk that comes with population growth. Similarly, territorial expansion

through imperialistic foreign policy increases not only the population but also usually the

population dispersion of a state. Attempts to impose military control over a heavily mountainous

region would seem to be particularly ill-advised. The significance of mountains as a stimulant to

civil war points up the folly of Soviet and American military involvement in Afghanistan.

6. Conclusion

Smith 10

Obviously there is much work still to be done. Besides the suggestions already made

above, it might also be useful to investigate birth rates and immigration rates as possible

causative variables. Further work should also be done on the causes of low-level conflict,

particularly between non-state actors. Even so, the findings of the literature so far have been

highly suggestive and relevant to US policy, especially given the US’s involvement in numerous

statebuilding projects around the world. The findings presented here suggest that the US should

seek to encourage fledgling states to adopt a pluralistic ideology, a strong, centralized model of

government, an extreme form of either democracy or autocracy, controls on population growth,

and a non-expansionistic foreign policy.

The findings described in this paper also suggest that US should be more selective about

which states to assist and which methods to use in rendering that assistance. In some states, for

example, extreme democratization may not be a realistic near-term goal. In other states, military

intervention may do serious damage to the economy (and thus the stability) of a country. A

lasting (and expensive) US military presence may be required to preserve peace in states

destabilized by military intervention. Simple human decency demands that the US militarily

intervene only in states where the conditions for long-term stability can be achieved before

popular American commitment to the project wanes. The US should also consider more

constructive kinds of intervention as well, such as economic stimulus and diplomatic negotiation

for favorable political change.

Smith 11

Table 1. Statistical Significance of Various Predictors of Civil War Onset

  Studies finding a factor significant for large-scale conflict

Studies finding a factor non-significant for large-scale conflict

Social (ethnic and religious) fractionalization*

(Collier and Hoeffler)  

Ethnic fractionalization (Hegre, Ellingsen, Gates, and Gleditsch)

(Fearon and Laitin), (Collier and Hoeffler), (Hegre and Sambanis), (Schneider and Weisehomeier)

Ethnic dominance (Collier and Hoeffler), (Hegre and Sambanis)

 

Ethnic polarization (Montalvo and Reynal-Querol) (Fearon and Laitin), (Østby), (Collier and Hoeffler), (Hegre and Sambanis), (Schneider and Weisehomeier)

Economic polarization   (Østby)Religious fractionalization

  (Fearon and Laitin), (Collier and Hoeffler), (Hegre and Sambanis), (Schneider and Weisehomeier)

Religious polarization   (Montalvo and Reynal-Querol), (Fearon and Laitin), (Schneider and Weisehomeier)

Islam   (Fearon and Laitin)Education inequalities between ethnic groups

(Østby)  

Linguistic or Religious Discrimination

  (Fearon and Laitin)

Regulation of Participation*

(Hegre and Sambanis)  

Polarization of educational access

(Østby)  

Democracy* (Benson and Kugler), (Reynal-Querol)

(Hegre, Ellingsen, Gates, and Gleditsch), (Fearon and Laitin), (Collier and Hoeffler), (Hegre and Sambanis), (Schneider and Weisehomeier)

Political extraction of govt*

(Benson and Kugler)  

Political extraction of opposition

(Benson and Kugler)  

Inconsistent Polity (Hegre, Ellingsen, Gates, and Gleditsch), (Fearon and Laitin (Hegre and Sambanis)

 

Recent instability, regime change, or independence

(Hegre, Ellingsen, Gates, and Gleditsch), (Fearon and Laitin), (Hegre and Sambanis)

 

Population (Fearon and Laitin), (Collier and Hoeffler), (Hegre and Sambanis), (Schneider and Weisehomeier)

(Østby)

GDP per capita* (Fearon and Laitin), (Østby), (Collier and Hoeffler), (Hegre and Sambanis)

(Schneider and Weisehomeier)

Development (Hegre, Ellingsen, Gates, and Gleditsch)

 

Time at peace (Collier and Hoeffler) (Hegre and Sambanis)Presidential system* (Hegre and Sambanis)  Inclusiveness of (Reynal-Querol)

Smith 12

government*Centralization*   (Hegre and Sambanis)Neighborhood political economy

(Hegre and Sambanis)  

Region (Hegre and Sambanis) (Fearon and Laitin)Neighborhood at war (Hegre and Sambanis) (Fearon and Laitin)GDP growth* (Collier and Hoeffler), (Hegre and

Sambanis) 

Economic policy   (Fearon and Laitin), (Hegre and Sambanis)Social welfare   (Hegre and Sambanis)Oil exports (Fearon and Laitin), (Collier and

Hoeffler)(Hegre and Sambanis)

Primary commodity exports

(Collier and Hoeffler) (Fearon and Laitin), (Hegre and Sambanis), (Schneider and Weisehomeier)

Rough Terrain (Fearon and Laitin), (Hegre and Sambanis)

(Collier and Hoeffler), (Schneider and Weisehomeier)

Noncontiguous territory   (Fearon and Laitin), (Hegre and Sambanis), (Schneider and Weisehomeier)

Population density (Collier and Hoeffler), (Hegre and Sambanis)Population dispersion (Collier and Hoeffler)Militarization* (Hegre and Sambanis)  Decade (Hegre, Ellingsen, Gates, and

Gleditsch), (Hegre and Sambanis)(Fearon and Laitin), (Collier and Hoeffler)

Colonial war   (Hegre and Sambanis)Male education* (Collier and Hoeffler) (Fearon and Laitin)Proportion of young males in population

  (Fearon and Laitin)

Vertical income inequality

  (Fearon and Laitin), (Østby), (Collier and Hoeffler)

Availability of foreign military support*

(Fearon and Laitin)  

Diasporas** (Collier and Hoeffler)  

* Inversely related to conflict onset.

** Significant only for repeat conflict.

Smith 13

Table 2. Statistical Significance of Various Predictors of Internal Armed Conflict Onset

  Significant for small-scale conflict Non-significant for small-scale conflict

Ethnic fractionalization (Hegre and Sambanis) (Schneider and Weisehomeier)Ethnic dominance   (Hegre and Sambanis)Ethnic polarization   (Hegre and Sambanis), (Schneider

and Weisehomeier)Religious fractionaliztion (Hegre and Sambanis) (Schneider and Weisehomeier)Religious polarization   (Schneider and Weisehomeier)Regulation of Participation (Hegre and Sambanis)  Democracy*   (Hegre and Sambanis), (Schneider

and Weisehomeier)Inconsistent Polity   (Hegre and Sambanis)Recent instability, regime change, or independence

(Hegre and Sambanis)  

Population (Hegre and Sambanis), (Schneider and Weisehomeier)

 

GDP per capita* (Hegre and Sambanis), (Schneider and Weisehomeier)

 

Development    Time at peace   (Hegre and Sambanis)Presidential system*   (Hegre and Sambanis)Centralization* (Hegre and Sambanis)  Neighborhood political economy   (Hegre and Sambanis)Region (Hegre and Sambanis)  Neighborhood at war (Hegre and Sambanis)  GDP growth* (Hegre and Sambanis)  Economic policy   (Hegre and Sambanis)Social welfare   (Hegre and Sambanis)Oil exports (Hegre and Sambanis)  Primary commodity exports (Hegre and Sambanis) (Schneider and Weisehomeier)Rough Terrain   (Hegre and Sambanis), (Schneider

and Weisehomeier)Noncontiguous territory   (Hegre and Sambanis), (Schneider

and Weisehomeier)Population density*   (Hegre and Sambanis)Militarization* (Hegre and Sambanis)  Decade (Hegre and Sambanis)  Colonial war   (Hegre and Sambanis)

* Inversely related to conflict onset.

Smith 14

Works Cited

Benson, Michelle and Jacek Kugler. “Power Parity, Democracy, and the Severity of Internal

Violence.” Journal of Conflict Resolution 42.2 (1998): 196-209. Print.

“Codebook: QoG Time Series and Cross-section Datasets.” Quality of Government Institute at

Göteborg U, 15 Nov. 2006. Web. 15 Oct. 2010.

Collier, Paul and Anke Hoeffler. “Greed and Grievance in Civil War.” Oxford Economic Papers

56.4 (2004): 563-95. Print.

Esteban, Joan and Debraj Ray. “Polarization, Fractionalization, and Conflict.” Journal of Peace

Research 45 (2008): 163-82. Print.

Fearon, James D. and David D. Laitin. “Ethnicity, Insurgency and Civil War.” American

Political Science Review 97.1 (2003): 75-90. Print.

Hegre, Havard and Nicholas Sambanis. “Sensitivity Analysis of Empirical Results on Civil War

Onset.” Journal of Conflict Resolution 50.4 (2006): 508-535. Print.

Lindberg, Carter. The European Reformations. Malden: Blackwell Publishing, 1996. Print.

Montalvo, Jose G. and Marta Reynal-Querol. “Ethnic Polarization, Potential Conflict, and Civil

Wars.” American Economic Review 95.3 (2005): 796-816. Print.

Noll, Mark A. God and Race in American Politics. Princeton: Princeton UP, 2008. Print.

Østby, Gudrun. “Polarization, Horizontal Inequalities and Violent Civil Conflict.” Journal of

Peace Research 45.2 (2008): 143-62. Print.

Przeworski, Adam, Michael E. Alvarez, José Antonio Cheibub, and Fernando Limongi.

Democracy and Development: Political Systems and Well-Being in the World, 1950-

1990. Cambridge: Cambridge UP, 2000. Print.

Reynal-Querol, Marta. “Does Democracy Preempt Civil Wars?” European Journal of Political

Economy 25 (2005): 445-65. Print.

Smith 15

“Rwanda: How the Genocide Happened.” BBC News, 18 Dec. 2008. Web. 16 Oct. 2010.

Schmitt, Eric. “Many Sources Feed Taliban’s War Chest.” The New York Times, 18 Oct. 2009.

Web. 17 Oct. 2010.

Schneider, Gerald and Nina Weisehomeier. “Ethnic Polarization, Potential Conflict, and Civil

Wars: Comment.” 2006. Web. 10 Oct. 2010.

Wuthnow, Robert. America and the Challenges of Religious Diversity. Princeton: Princeton UP,

2005. Print.