Benjamin E. Bagozzi

Modeling Two Types of Peace: The Zero-inflated Ordered Probit (ZiOP) Model in Conflict Research

A growing body of applied research on political violence employs split-population models to address problems of zero inflation in conflict event counts and related binary dependent variables. Nevertheless, conflict researchers typically use standard ordered probit models to study discrete ordered dependent variables characterized by excessive zeros (e.g., levels of conflict). This study familiarizes conflict scholars with a recently proposed split-population model—the zero-inflated ordered probit (ZiOP) model—that explicitly addresses the econometric challenges that researchers face when using a “zero-inflated” ordered dependent variable. We show that the ZiOP model provides more than an econometric fix: it provides substantively rich information about the heterogeneous pool of “peace” observations that exist in zero-inflated ordinal variables that measure violent conflict. We demonstrate the usefulness of the model through Monte Carlo experiments and replications of published work and also show that the substantive effects of covariates derived from the ZiOP model can reveal nonmonotonic relationships between these covariates and one’s conflict probabilities of interest.

Data-based Computational Approaches to Forecasting Political Violence

The challenge of terrorism dates back centuries if not millennia. Until recently, the basic approaches to analyzing terrorism—historical analogy and monitoring the contemporary words and deeds of potential perpetrators—have changed little: the Roman authorities warily observing the Zealots in first-century Jerusalem could have easily traded places with the Roman authorities combatting the Red Brigades in twentieth century Italy.

From global to local, food insecurity is associated with contemporary armed conflicts

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.

Living off the land: The connection between cropland, food security, and violence against civilians:

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.

Droughts, Land Appropriation, and Rebel Violence in the Developing World

Scholars note that rebel atrocities against civilians often arise within rural areas in the developing 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 subnational level across the developing world, we find robust support for our game-theoretic model’s predictions.

On Malaria and the Duration of Civil War

Geographic factors such as rugged terrain and distance from capital cities are widely believed to prolong civil wars by enabling rebel groups to resist total defeat. This article argues that prevalence of malaria can similarly serve to asymmetrically enhance rebels’ defensive capabilities and thus prolong civil war. Malaria prevalence does so in three complementary ways. First, while malaria can inflict costs on both government and rebel troops, these costs are magnified for larger and denser human groups; thereby ensuring that the costs of malaria will often be higher among government troop deployments. Second, because government soldiers are rotated in and out of conflict zones whereas insurgents typically are not, the former are likely to have a higher nonimmune exposure rate than the latter, which further ensures that government forces will be more susceptible to contracting and spreading malaria. Third, malaria can also indirectly prolong civil war by helping to maintain a socio-geographic environment that is conducive to insurgency. These three complementary factors advantage rebel forces’ abilities to resist defeat by government forces and prolong civil conflicts. I empirically test these arguments by examining the duration of civil wars and find strong support for a prolonging effect of malaria on civil conflict.

Regional International Organizations and Individual Immigration Attitudes: Results from Finite Mixture Models

When are individuals more likely to support immigration? We suggest here that regional international organizations (IOs; for example, the European Union) publicly release reports about the scale and benefits of immigration to member states in the region in which these IOs operate. We argue that unlike individuals who are uninformed about immigration, informed individuals who have more knowledge of the main regional IO in which their country participates will be more likely to employ immigration reports released by their regional IO to construct their immigration attitudes. They will also perceive that these reports are credible. The credibility of these reports helps individuals with more knowledge about their region’s main IO to view immigrants favorably, which translates to support for immigration. We test our prediction by developing a finite mixture model that statistically accounts for the econometric challenges that emerge when uninformed individuals “save face” by disproportionately opting for the middle “status quo” category in ordinal survey response variables of immigration support. Results from the finite mixture model corroborate our prediction and are more reliable than estimates from a standard ordered probit model.

The IMF, Domestic Public Sector Banks, and Currency Crises in Developing States

The stabilization programs of the International Monetary Fund (IMF)—which are often designed to prevent currency crashes and promote exchange rate stability—frequently fail to prevent currency crises in program-recipient developing countries. This leads to the following puzzle: when do IMF programs fail to prevent currency crises in developing states that turn to the Fund for assistance? We suggest that the likelihood that a currency crisis may occur under an IMF program depends on the market concentration of public sector banks in program-participating developing countries: the higher the market concentration of public banks in a program recipient nation, the more likely that the IMF program will be associated with a currency crisis. Specifically, if the market concentration of public banks in a program-participating developing country is high, then banks will compel the government to renege on its commitment to implement banking sector reforms. This induces a financial panic among investors that leads to a currency crisis. Statistical tests from a sample of developing countries provide robust support for our hypothesis.

The Spatial Properties of Radical Environmental Organizations in the UK: Do or Die!

Radical environmental groups and their members have a wide and varied agenda which often encompasses both local and global issues. In their efforts to call attention to environmental problems, communicate with like-minded groups, and mobilize support for their activities, radical environmental organizations also produce an enormous amount of text, which can be used to estimate the complex communications and task-based networks that underlie these organizations. Moreover, the tactics employed to garnish attention for these groups’ agenda can range from peaceful activities such as information dissemination to violent activities such as fire-bombing buildings. To obtain these varied objectives, radical environmental organizations must harness their networks, which have an important spatial component that structures their ability to communicate, coordinate and act on any given agenda item. Here, we analyze a network built from communications and information provided by the semi-annual “Do or Die” (DoD) magazine published in the UK over a 10 year period in the late 1990s and early 2000s. We first employ structural topic model methods to discover violent and nonviolent actors within the larger environmental community. Using this designation, we then compare the spatial structure of these groups, finding that violent groups are especially likely to engage in coordination and/or communication if they are sufficiently close, but exhibit a quickly decreasing probability of interaction over even a few kilometers. Further, violent and nonviolent groups each have a higher probability of coordination with their own group than across groups over even short distances. In these respects, we see that violent groups are especially local in their organization and that their geographic reach is likely very limited. This suggests that nonviolent environmental groups seek each other out over both large and short distances for communication and coordination, but violent groups tend to be highly localized.

The baseline-inflated multinomial logit model for international relations research

International relations scholars are often interested in nominal dependent variables, and commonly analyze such variables with multinomial logit (MNL) models that treat status quo outcomes (e.g. “peace”) as a homogeneous baseline-choice category. However, recent studies of zero-inflation processes within international relations suggest that these baseline cases may often arise from two distinct sources. Specifically, some status quo responses are likely to correspond to observations that actively opted for this choice over all others, while the remaining status quo outcomes are likely to arise from observations that were unable to realistically register a non-status quo choice under any reasonable circumstances. Including both sets of responses within an MNL model’s baseline category can bias the estimated effects of covariates, leading to faulty inferences. As a solution to this problem, this study considers a recently proposed baseline-inflated MNL (BIMNL) model that explicitly estimates and tests for heterogeneous populations of status quo observations. After discussing the model and its theoretical underpinnings, I demonstrate the BIMNL’s utility through replications of two existing studies of political violence and cooperation within the areas of international relations and civil war.