Peer-Reviewed Books

Mukherjee, Bumba and Ore Koren. 2018. The Politics of Mass Killing in Autocratic Regimes. Cham, Switzerland: Palgrave Macmillan/Springer-Nature.

This book develops a detailed, disaggregated theoretical and empirical framework that explains variations in mass killing by authoritarian regimes globally, with a specific focus on Pakistan, Indonesia, and Malaysia. Using a combination of game-theoretic, statistical, and qualitative approaches, this project explicates when civilians within nondemocratic states will mobilize against the ruling elite, and when such mobilization will result in mass killing. In doing so, it illustrates the important role urbanization and food insecurity historically played, and will continue to play, in generating extreme forms of civilian victimization.

Peer-Reviewed Articles

Koren, Ore. “Quantifying the Disaggregated Impact of Atrocities on Socioeconomic Activity.” Accepted in Global Studies Quarterly.

Research on atrocities perpetrated against civilians often focuses on explaining political violence and identifying its determinants. Yet, our understanding of atrocities’ impact on socioeconomic outcomes is still limited, especially with regards to how these effects unfold at the local, rather than country, level. The present study undertakes a comprehensive evaluation of atrocities’ adverse impacts on local socioeconomic activity. I begin by reviewing literature on the impact of conflict, and violence against civilians specifically, on economic and political development. I then identify and discuss pathways linking atrocities with lower socioeconomic activity at the local level. To operationalize local socioeconomic activity, I rely on nighttime light emissions; to operationalize atrocities, I rely on data from the Worldwide Atrocity Dataset, which measures all events that resulted with at least five civilian deaths by location. To evaluate these impacts empirically, I estimate both ordinary least squares and generalized methods of moments (GMM) models, which account for potential endogeneity, on a sample measured at the localized- (.5 x .5-degree resolution) year level for the years 1997 – 2013. I find that, on average, an additional atrocity event corresponds to a decrease of 3-10% in local development levels the following year, compared with the baseline. Building on these findings, I discuss in detail research and policy implications. This study hence offers important lessons for our understanding of the effects of cruelty on political and economic phenomena, and especially its role in increasing inequalities within violence-affected zones, and across affected and nonaffected regions.

Koehnlein, Brittney  and Ore Koren. “COVID-19, State Capacity, and Violence by Nonstate Actors.” Accepted in Journal of Peace Research.

The COVID-19 pandemic has constrained the ability of states across the world to govern and control their territories. As the state reduces its activities, space opens for violent nonstate actors working for and against the state to fill the vacuum. Highlighting this trend, the present study evaluates the effects of COVID-19 and pandemics more broadly on attacks by nonstate actors. Our theory emphasizes the incentives of both rebels and pro-government nonstate actors (PGNs) to increase their attack frequency as disease spreads and the state retracts its governance activities to preserve resources needed elsewhere. In the first case, we highlight how the pandemic allows rebels to reduce asymmetries of power with respect to the military and establish themselves as a viable government alternative. In the second case, PGNs, which provide an alternative to militaries, are deployed to these contested spaces to thwart or preempt rebellion during the pandemic. Employing daily level data on the annual change in armed conflict and COVID-19 cases across 127 countries between 1 January 2020 and 15 June 2020, we test both claims using an econometric identification strategy. We do not find clear evidence that COVID-19 led to a higher frequency of rebel attacks, suggesting that these groups prefer to bolster their standing using nonviolent means, or avoid fighting and preserve their resources. In contrast, we find that the frequency of PGN attacks has increased with COVID-19 prevalence compared with last year. Case studies of insurgent and PGN activity in Afghanistan and Nigeria lend additional support to these results, illustrating some underlying mechanisms. Our findings explore overlooked challenges that pandemics and other disasters pose to conflict mitigation and the role PGNs play in these contexts.

Sarbahi, Anoop, and Ore Koren. “The Moderating Effect of Democracy on Climate-Induced Social Conflict: Evidence from Indian Districts.” Forthcoming in Political Research Quarterly. 

Do political institutions moderate the effect of environmental stress on social conflict? We posit that while the frequency of social conflict in developing agrarian states can increase during drought, strong democratic institutions reduce conflict and can facilitate cooperation, reversing this effect. This hypothesis is tested on a sample of all districts in India over a period from 2001–2014. The dependent variable captures the number of crimes perpetrated against scheduled castes – so-called “untouchables”– and scheduled tribes – India’s indigenous groups – during a given district-year. When the effect of drought is moderated using a local electoral competition index, findings show that although droughts increase the frequency of social conflicts where political institutions are weak, this effect is eliminated where political institutions are strong. The results are robust to alternative operationalization choices. Our findings thus have relevance both to scholars of the climate-conflict nexus and to policymakers working to address climate change’s effects.

Koren, Ore  Sumit Ganguly, and Aashna Kahnna. “Fragile States, Technological Capacity, and Increased Terrorist Activity.” Studies in Conflict & Terrorism. Published online 2021.

Research on terrorism disagrees on whether terrorist activity is at its highest in collapsed states, which are more hospitable to such activities, or whether terrorism increases in more capable states. We revisit this discussion by theorizing an interactive relationship: terrorists prefer to operate in politically-hospitable states, but their attack frequency within these states increases with greater technological capacity, which allows them to expand their military, recruitment, and financing operations. We analyze 27,018 terrorist incidents using regression and causal inference models, conduct a case study, and find robust support for this interactive logic. Our conclusions outline implications for policy and academic work.

Bagozzi, Benjamin E., and Ore Koren. “The Diplomatic Burden of Pandemics: Lessons from Malaria.” Political Science Research and Methods. Published online 2021. 

This note seeks to understand the extent of the disruptions to international relations caused by pandemics, focusing on one globally-endemic disease: malaria. We posit that longstanding diseases such as malaria have the potential to undermine the political ties of nation states, as well as the many benefits of these connections. Our argument is tested empirically using both directed-dyadic and monadic data, while incorporating methods that account for endogeneity and other relevant concerns. We find that the geographic malaria rates of a country not only serve to historically discourage foreign governments from establishing diplomatic outposts on a country’s soil, but also lead to an aggregate decrease in the total diplomatic missions that a country receives. We then discuss the current implications of these findings.


Koren, Ore, and Bumba Mukherjee. “Economic Crises, Civilian Mobilization, and Repression in Developing States.” Conflict Management and Peace Science. Published online 2021. 

Research on the causes of repression had limited success in connecting economic crises to state-led violence. We develop an explanation for violent government repression in urban areas, which links the importance of urban infrastructure in enabling civilians to wage an effective opposition campaign with the stress caused by economic crisis, empirically validating the underlying mechanisms using disaggregated geospatial data. We then confirm the empirical expectation that governments will violently repress during times of economic crisis where the civilians’ capacity to wage a collective action campaign is high using a disaggregated global sample of urban areas within developing states.


Anderson, Noel, Benjamin E. Bagozzi, and Ore Koren. “Addressing Monotone Likelihood in Duration Modeling of Political Events.” British Journal of Political Science 51(4): 1654–1671

This article provides an accessible introduction to the phenomenon of monotone likelihood in duration modeling of political events. Monotone likelihood arises when covariate values are monotonic when ordered according to failure time, causing parameter estimates to diverge toward infinity. Within political science duration model applications, this problem leads to misinterpretation, model misspecification, and omitted variable biases, among other issues. Using a combination of mathematical exposition, Monte Carlo simulations, and empirical applications, this article illustrates the advantages of Firth’s penalized maximum likelihood estimation in resolving the methodological complications underlying monotone likelihood. Our results identify the conditions under which monotone likelihood is most acute and provide guidance for political scientists applying duration modeling techniques in their empirical research.

Koren, Ore, and Bumba Mukherjee. 2021. “Civil Dissent and Repression: An Agency-Centric Perspective.”  Journal of Global Security Studies 6(3): ogaa051.

Do governments make a strategic choice in deciding what type of security agent to use for repression? Research acknowledges the role of auxiliary groups such as militias in repression, yet surprisingly little attention is given to the state’s formal domestic security agents, such as the police. We show that formal security organizations and auxiliary groups enhance the government’s ability to repress by acting as strategic complements. As the better-regulated force, formal agents are often employed against violent riots, when regimes worry more about the ability to control the agents and their behavior more than about being visibly linked to the violence. In contrast, auxiliaries are often used to repress nonviolent campaigns, when the government seeks to benefit from agency loss in order not to be associated with the violence, which can be costly in these contexts. We empirically verify these linkages on country-month data for Africa using panel vector-autoregression (pVAR), which accounts for endogeneity, not only between the dependent and independent variables, but also the dependent variables. We complement these statistical results with case-based evidence and descriptive original data from non-African countries.

Koren, Ore, Benjamin E. Bagozzi, and Thomas Benson. 2021. “Food and Water Insecurity as Causes of Social Unrest: Evidence from Geolocated Twitter Data.”  Journal of Peace Research 58(1): 67-82. 

Research often fails to account for the specific pathways by which climatic factors can cause so- cial unrest. One challenge lies in understanding the distinct effects of food insecurity and water insecurity—which we term “staple insecurities”—while accounting for their interrelated nature, especially at high-resolution spatio-temporal scales. To unpack these dynamics, we leverage geolocated Twitter data across urban areas in Kenya and deploy a supervised machine learning approach to separately identify geolocated tweets concerning food and water insecurity, in both English and Swahili. The data are then aggregated to create daily measures of food and water insecurity for standardized grid-cells to examine how perceived food insecurity moderates and/or reinforces perceived water insecurity’s impacts on social unrest, and vice versa. Our findings suggest that food and water insecurities’ respective effects should be interpreted as mutually reinforcing—in compelling citizens to take to the streets—rather than as independent. Those concerned with climate change’s impact on conflict should hence endeavor to jointly account for both forms of insecurity, and their interactive effects.

Koren, Ore. 2019. “Food Resources and Strategic Conflict.” Journal of Conflict Resolution 63(10): 2236-2261.

A growing number of studies draw linkages between violent conflict and food scarcities. Yet, evidence suggests that within states, conflict revolves around food resources abundance. I develop an explanation for how the competition over food resources conditions the strategic behaviors of three actors: rebels, civilian producers who grow crops, and state forces. Using a statistical-strategic model, I validate my theory at the subnational level on new high specificity spatial data on staple crop access and productivity in Africa for the years 1998-2008 (and use the estimates to forecast conflict on out-of-sample data for 2009-2010). In line with theoretical expectations, local variations in food productivity have a positive, statistically significant, and substantive effect on the strategic behaviors of different actors. These findings suggest that the imperative for food denial as a micro level tactic in civil war should be more seriously incorporated into the work of scholars and policymakers.

Koren, Ore. 2019. “Food, State Power, and Rebellion: The Case of Maize.” International Interactions 45(1): 170-197.

Why do rebellions occur and persist in some countries but not in others? Evidence shows that natural resources affect the fighting capacity of rebel groups, yet by focusing on lucrative resources that are rare in most rebellion-afflicted countries, such as oil and diamonds, scholars neglected one necessary input for rebellion: staple crops. Focusing on maize, the world’s most prevalent staple, this study argues that, as one of the most important resources for rebel groups, maize can have a destabilizing effect on the state’s ability to thwart rebellion. These claims are corroborated statistically on a new time-varying, high-resolution global dataset of staple crop productivity, and then qualitatively through analysis of archival records on the Mau Mau rebellion. In identifying an overlooked, global linkage between agricultural abundance, state capacity, and intrastate violence, this study explains strong geographical and temporal variations in rebellions at both the subnational and global levels.

Koren, Ore. 2018. “Food Abundance and Violent Conflict in Africa.” American Journal of Agricultural Economics 100(4): 981-1006.

Scholars debate whether climate change has a consistent effect on the likelihood of armed conflict in Africa. One major pathway by which climatic variability is hypothesized to increase conflict is by decreasing food availability. However, limitations on food access at both the local and national level in many developing African countries force most armed groups and communities to depend on locally produced food. These actors are therefore likely to use violence to establish control over more food resources or be stationed where more food is available, suggesting that food abundance might also be driving conflict. The present study employs novel data on wheat and maize yields in Africa measured at the very local level to empirically evaluate this hypothesis on a highly disaggregated conflict indicator. To account for the endogenous relationship between conflict and food production, average local levels of drought are used as an instrument. The findings show that, contrary to previous expectations, conflict is driven by higher yields, on average, and not by scarcity.

Koren, Ore, and Anoop Sarbahi. 2018. “State Capacity, Insurgency and Civil War: A Disaggregated Analysis.” International Studies Quarterly 62(2): 274-288.

Country-level indicators such as gross domestic product, bureaucratic quality, and military spending are frequently used to approximate state capacity. These factors capture the aggregate level of state capacity, but do not adequately approximate the actual distribution of capacity within states. Intra-state variations in state capacity are critical to understanding the relationship between state capacity and civil war. We offer nighttime light emissions as a measure of state capacity to differentiate its impact on civil war onset within the country from its effect at the country level. We articulate pathways linking the distribution of nighttime light with the expansion of state capacity, and validate our indicator against other measures at different levels of disaggregation across multiple contexts. Contrary to conventional wisdom, we find that civil wars are more likely to erupt where the state exercises more control. We advance three mechanisms accounting for this counterintuitive finding: rebel gravitation, elite fragmentation, and expansion reaction. In the first scenario, state presence attracts insurgent activities. In the second, insurgents emerge as a result of the fragmentation of political elites. In the third, anti-state groups react violently to the state penetrating into a given territory. Finally, we validate these mechanisms using evidence from sub-Saharan Africa.

Koren, Ore. 2017. “Why Insurgents Kill Civilians in Capital Cities: A Disaggregated Analysis of Mechanisms and Trends.” Political Geography 61: 237-252.

Research into the causes of violence against civilians has increased significantly in recent years, yet the mechanisms governing spatial patterns of victimization remain poorly under- stood. My investigation explores if and why one specific locality, capital cities, experiences a higher frequency of violence against civilians perpetrated by armed insurgent organizations. I argue that the political value associated with capitals allows these groups to asymmetrically impose higher costs on the regime by targeting civilians in these localities. I lay out and val- idate three specific mechanisms to explain this pattern: elite coercion, popular intimidation, and international persuasion. In the first scenario insurgents aim to influence domestic elites directly. In the second, they aim is to affect domestic civilians’ resolve. In the third, they seek to influence international audiences. Using new geolocated global atrocities data for the years 1996-2009, I evaluate this linkage by employing different methodological approaches and accounting for potential reporting biases. Finally, I show that ethnic and secessionist wars are more likely to experience atrocities in the capital compared with other conflicts. The findings illustrate potential benefits from explaining the temporal and spatial variation in violence by insurgents, with a focus on strategic conditions and power asymmetries.


Koren, Ore, and Benjamin E. Bagozzi. 2017. “Living Off The Land: The Connection between Cropland, Food Security, and Violence against Civilians.” Journal of Peace Research 54(3): 351-364.

Food security has attracted widespread attention in recent years. Yet, despite preliminary evidence connecting food insecurity to political violence, we lack a systematic understanding of the relationship(s) between local food resources and violence against civilians. This study develops a food-security based theory to explain the significant variation that we observe in violence against civilians across both time and subnational geographic space. We argue that combatants, be they government or rebel actors, often must turn to local agricultural resources for sustenance. During times of relative peace, armed actors and civilians have long time horizons, and the prospects of repeated interactions thereby promote a strategy of co-optation to obtain food resources. However, the existence of immediate conflict in a region leads armed actors to discount the benefits of future interactions in favor of obtaining food immediately, using violence if necessary. In estimating a series of statistical models on a sample of all African countries (1997-2009), we find robust support for our expectations: cropland increases the frequency of violence against civilians during periods of conflict, but has an added pacifying effect during times of peace.

Bagozzi, Benjamin E., Ore Koren, and Bumba Mukherjee. 2017. “Droughts, Land Appropriation, and Rebel Violence in The Developing World.” Journal of Politics 79(3): 1057-1072.

Scholars note that rebel atrocities against civilians often arise within rural areas in the de- veloping world. This characterization is not far-fetched, and recent data show that rebel atrocities do predominately occur within rural agricultural regions. Yet, the frequency of such incidents also varies substantially across different agricultural regions and years. What accounts for this observed variation in rebel-perpetrated atrocities against civilians within agricultural areas in developing countries? We develop a formal model to address this question, which contends that severe droughts can decrease food availability, prompting civilians to allocate food for immediate consumption and become increasingly willing to defend their diminishing supplies against rebels. This leads rebels to preempt the civilians’ defensive efforts by committing atrocities, which forcibly separate civilians from their lands and food stockpiles. In empirically testing this hypothesis at the sub-national level across the developing world, we find robust support for our game-theoretic model’s predictions.

Koren, Ore. 2017. “Means to an end: Pro-government militias as a predictive indicator of strategic mass killing.” Conflict Management and Peace Science 34(5): 461-484. (Earlier 2015 online version — DOI: 10.1177/0738894215600385).

Forecasting models of state-led mass killing are limited in their use of structural indicators, despite a large body of research that emphasizes the importance of agency and security repertoires in conditioning political violence. I seek to overcome these limitations by developing a theoretical and statistical framework that highlights the advantages of using pro-government militias (PGMs) as a predictive indicator in forecasting models of state-led mass killing. I argue that PGMs can lower the potential costs associated with mass killing for a regime faced with an internal threat, and might hence ‘‘tip the balance’’ in its favor. In estimating a series of statistical models and their receiver–operator characteristic curves to evaluate this hypothesis globally for the years 1981–2007, focusing on 270 internal threat episodes, I find robust support for my expectations: including PGM indicators in state-led mass killing models significantly improves their predictive strength. Moreover, these results hold even when coefficient estimates produced by in-sample data are used to predict state-led mass killing in cross-validation and out-of-sample data for the years 2008–2013. This study hence provides an introductory demonstration of the potential advantages of including security repertoires, in addition to structural factors, in forecasting models.

Koren, Ore, and Benjamin E. Bagozzi. 2016. “From Global to Local, Food Insecurity is Associated with Contemporary Armed Conflict.” Food Security 8(5): 999-1010.

Food security has attracted widespread attention in recent years. Yet, scientists and practitioners have predominately understood food security in terms of dietary energy availability and nutrient deficiencies, rather than in terms of food security’s consequential implications for social and political violence. The present study offers the first global evaluation of the effects of food insecurity on local conflict dynamics. An economic approach is adopted to empirically evaluate the degree to which food insecurity concerns produce an independent effect on armed conflict using comprehensive geographic data. Specifically, two agricultural output measures – a geographic area’s extent of cropland and a given agricultural location’s amount of cropland per capita – are used to respectively measure the access to and availability of (i.e., the demand and supply of) food in a given region. Findings show that food insecurity measures are robustly associated with the occurrence of contemporary armed conflict.

Koren, Ore. 2014. “Military structure, civil disobedience, and military violence.” Terrorism & Political Violence 26(4): 688-712.

In this article, I argue that factors inherent to the structure of a military organization and their relationship with the political leadership play a role in the organization’s ten- dency to perpetrate violence against civilians during civil disobedience campaigns. To examine this hypothesis, I conducted a three-phased statistical analysis on a database containing 97 campaigns that took place between 1972 and 2012. In the first phase, I examined the relationship between military centric factors and violent crackdowns. In the second phase, I examined the relationship between military centric factors and mass killing. In the third stage, I examined the relationship between two specific types of discrimination in the military and mass killing. I found strong evidence supporting the hypothesis mentioned above. High-risk militaries that served a militarized regime, contained loosely regulated or indoctrinated paramilitaries, and discriminated against the protesting group, were much more likely to perpetrate violence against civilians during civil disobedience campaigns than low-risk militaries. The conclusions of this study suggest that further examination of the military’s role in perpetrating violence against civilians during protests and conflict may provide some novel findings.

Non-Peer-Reviewed Articles

Koren, Ore. “Review of Why we Fight by Mike Martin (London: Hurst & Company, 2019).” Forthcoming at the Journal of Political and Military Sociology (solicited).