Publications in 2015

Croicu, Mihai and Nils B. Weidmann. "Improving the Selection of News Reports for Event Coding Using Ensemble Classification."

Research and Politics 2(4) 

Manual coding of political events from news reports is extremely expensive and time-consuming, whereas completely automatic coding has limitations when it comes to the precision and granularity of the data collected. In this paper, we introduce an alternative strategy by establishing a semi-automatic pipeline, where an automatic classification system eliminates irrelevant source material before further coding is done by humans. Our pipeline relies on a high-performance supervised heterogeneous ensemble classifier working on extremely unbalanced training classes. Deployed to the Mass Mobilization on Autocracies database on protest, the system it is able to reduce the number of source articles to be human-coded by more than half, while keeping over 90% of the relevant material. 

Cederman, Lars-Erik, Nils B. Weidmann and Nils-Christian Bormann. "Triangulating Horizontal Inequality: Toward Improved Conflict Analysis." 

Journal of Peace Research 52(6)

Does economic inequality cause civil war? Deviating from individualist measures of inequality such as the Gini coefficient, recent studies have found a statistical link between group-level inequalities and conflict onset. Yet, this connection remains controversial, not the least because of the difficulties associated with conceptualizing and measuring group-level differences in development. In an effort to overcome weaknesses afflicting specific methods of measurement, we introduce a new composite indicator that exploits the strengths of three sources of data. The first step of our method combines geocoded data from the G-Econ project with luminosity data from satellites. In a second step, we bring together the combined spatial values with survey estimates in order to arrive at an improved measure of group-level inequality that is both more accurate and robust than any one of the component measures. We evaluate the effect of the combined indicator and its components on the onset of civil violence. As expected, the combined index yields stronger results as more information becomes available, thus confirming the initial hypothesis that horizontal economic inequality does drive conflict in the case of groups that are relatively compared to the country average. Furthermore, these findings appear to be considerably more robust than those relying on a single data source.     

Vüllers, Johannes, Birte Pfeiffer and Matthias Basedau. "Measuring the Ambivalence of Religion: Introducing the Religion and Conflict in Developing Countries (RCDC) Dataset."

International Interactions 41(5) 

Despite ample anecdotal evidence, previous research on violent conflict has found little evidence that religion is an important factor in organized violence. Quantitative work in this area has been largely confined to the interreligious character of conflict and measures of religious diversity, and has strongly neglected the peace aspect of religion. The Religion and Conflict in Developing Countries Dataset (RCDC) helps to fill this gap with innovative and fine-grained data for 130 developing countries between 1990 and 2010. RCDC includes four types of religious violence (assaults on religious targets, attacks by religious actors, clashes between religious communities, and clashes with the state). In addition, RCDC contains data on interreligious networks and peace initiatives. This paper demonstrates the usefulness of RCDC by applying our data to a preliminary analysis. The results indicate that interreligious networks are a reaction to identity overlaps and previous interreligious conflict.

Kuhn, Patrick and Nils B. Weidmann. "Unequal We Fight: Between- and Within-Group Inequality and Ethnic Civil War."

Political Science Research and Methods 3(3) 

When and why ethnic groups rebel remains a central puzzle in the civil war literature. In this paper we examine how different types of inequalities affect both an ethnic group’s willingness and opportunity to fight. We argue that political and economic inter-group inequalities motivate ethnic groups to initiate a fight against the state, and that intra-group economic inequality lowers their elite’s costs of providing the necessary material and/or purposive incentives to overcome collective action problems inherent to rebel recruitment. We therefore predict that internally unequal ethnic groups excluded from power and/or significantly richer or poorer relative to the country’s average are most likely to engage in a civil war. To assess our claim empirically, we develop a new global measure of economic inequality by combining high resolution satellite images of light emissions, spatial population data, and geocoded ethnic settlement areas. After validating our measure at the country- and group-level we include it in a standard statistical model of civil war onset and find considerable support for our theoretical prediction: greater economic inequality within an ethnic group significantly increases the risk of conflict, especially if political or economic inequalities between groups provide a motive.  

Weidmann, Nils B. "On the Accuracy of Media-based Conflict Event Data."

Journal of Conflict Resolution 59(6)

Empirical researchers of civil war rarely collect data on violence themselves, and instead rely on other sources of information. One frequently-used source is media reports, which serve as the basis for many ongoing data projects in the discipline. However, news reports rarely cover a conflict comprehensively and objectively, and may therefore be prone to various reporting issues. This paper provides an analysis of the accuracy of information given in news reports. In particular, if focuses on two types of "hard facts" that event datasets require: the location of an event, and its severity. By linking media reports to first-hand accounts from a military database, the paper does two things: (i) it analyses the determinants of inaccuracy, and confirms the expectation that events with a low number of observers tend to have higher reporting inaccuracies, and (ii), it assesses the magnitude of these inaccuracies and the implications for creating event datasets from media reports.  

Ottmann, Martin and Johannes Vüllers. “The Power-Sharing Event Dataset (PSED): A New Dataset on the Promises and Practices of Power-Sharing in Post-Conflict Countries.”

Conflict Management and Peace Science 32(3) 

Past research on the relationship between power-sharing arrangements and the recurrence of civil conflict has primarily analyzed the promises of power-sharing stipulated in peace agreements. What happens afterwards, however, has not yet been sufficiently explored. This represents a major research gap, as the actual practices of power-sharing in post-conflict countries are likely to be influential in the possibility of civil conflict recurring. To address this shortcoming, we present a new global dataset on the promises and practices of power-sharing between the government of a state and former rebels in post-conflict countries. The collected data captures if, when and how power-sharing institutions have been promised and/or put into place, and whether they have subsequently been modified or abolished. The dataset encompasses every peace agreement signed after the cessation of a civil conflict in the years between 1989 and 2006, and covers a five-year period after the signature of each of these agreements (unless violence recurred earlier). The unit of analysis is the government–rebel dyad during the post-conflict period and data is recorded in an event data format. A first analysis of the Power-Sharing Event Dataset (PSED) reveals that the effects of the promises of power-sharing on civil conflict recurrence follow a different logic than the effects of their practices. This finding emphasizes the necessity for in-depth analyses of post- conflict situations for which the PSED provides the necessary data. 

Vüllers, Johannes and Sandra Destradi. “Gewaltfreie Widerstandsbewegungen und ihre Erfolgsbedingungen.“

Zeitschrift für Friedens- und Konfliktforschung 4(1) 

The growing importance of nonviolent resistance movements, underscored by recent developments from the Arab spring to the initially nonviolent protests in Ukraine, has resulted in a growing body of research. This literature review provides an overview of the most recent research on nonviolent resistance, which has developed at the crossroads of peace and conflict studies and social movement research. We first discuss different protest types and delineate the characteristics of nonviolent resistance movements. Subsequently, we focus on the explanations for the success of such movements. These include the number of people protesting, the ability of the movement to innovate its tactics, the goals of nonviolent resistance, the reactions of the state, shifting loyalties among the state security forces, and international support for the nonviolent resistance movement. Based on these findings of the recent literature, we discuss possible new avenues for research.  

De Juan, Alexander, Jan H. Pierskalla and Johannes Vüllers. “The Pacifying Effects of Local Religious Institutions: An Analysis of Communal Violence in Indonesia.“

Political Research Quarterly 68(2)  

This paper tests whether local religious institutions have a dampening effect on the probability of communal violence. It argues that a dense layer of institutions strengthens horizontal and vertical contacts and networks within religious communities. Horizontal linkages help to bridge social, economic, and ethnic divisions. Vertical contacts enable religious leaders to stay informed about communal grievances among their followers and to coordinate conflict resolution attempts. In our analysis of over 60,000 villages in Indonesia, we are able to document a statistically significant and substantively meaningful negative effect of the density of local religious institutions on the probability of mass fighting. This effect is robust to the inclusion of an exhaustive list of confounding variables and alternative measures of violence. 

Shapiro, Jacob N. and Nils B. Weidmann. "Is the Phone Mightier than the Sword? Cell Phones and Insurgent Violence in Iraq."

International Organization 69(2) 

Does improved communication as provided by modern cell phone technology affect the production of violence during insurgencies? A priori predictions are ambiguous; introducing cell phones can enhance insurgent communications but can also make it easier for the population to share information with counterinsurgents and creates passive signals intelligence collection opportunities. We provide the first systematic micro-level test of the effect of cell phone communication on conflict using data on Iraq’s cell phone network and event data on violence. We show that increased mobile communications reduced insurgent violence in Iraq, both at the district level and for specific local coverage areas. The results provide support for models of insurgency that focus on the provision of information by non-combatants as the key constraint on violent groups and highlight the fact that small changes in the transaction costs of cooperating with the government can have large macro effects on conflict. 

Weidmann, Nils B. "Communication, Technology, and Political Conflict: Introduction to the Special Issue."

Journal of Peace Research 52(3) 

Modern communication technology is emerging rapidly, with tremendous social implications. The key innovations introduced by this technology include the increased pervasiveness and the rich nature of digitally transmitted infor- mation, and a new type of network structure over which it is disseminated. The articles in this special issue present theoretical and empirical research on the relationship between communication technology and political conflict and violence. There are different pathways through which this can happen: technology can facilitate collective action, but at the same time give governments the opportunity to censor content and gather intelligence about dissidents. Also, audience effects can be introduced by the rich and instant transmission of information from conflict regions. The contributions to this special issue can be divided into three groups. A first group of articles looks at the effects of ‘old’ communication technologies with state-of-the-art methods, which is necessary to see if the effects of modern technology really differ. A second category of articles focuses on ‘new’ communication technologies, and try to assess their effect on conflict both theoretically and empirically. The third and last category reverses this question, and looks at the reflection of war and violence in (traditional and new) media channels. 

Rød, Espen Geelmuyden and Nils B. Weidmann. "Empowering Activists or Autocrats? The Internet in Authoritarian Regimes."

Journal of Peace Research 52(3) 

The reported role of social media in recent popular uprisings against Arab autocrats has fueled the notion of "liberation technology", namely that information and communication technology (ICT) facilitates organization of anti-government movements in autocracies. Less optimistic observers, on the other hand, contend that ICT is a tool of repression in the hands of autocrats, imposing further restrictions on political and social liberties. We investigate whether the liberation- or the repression-technology perspective can better explain empirically observed patterns. To this end, we analyze two outcomes. First, we look at which countries are more likely to adopt and expand the Internet. In line with the repression technology expectation, we find that regimes aiming to prevent any independent public sphere are more likely to introduce the Internet. Second, we study the effects of the Internet on changes towards democracy. This analysis reveals no effect of the Internet on political institutions. These findings provide moderate support for the "repression technology" perspective, and suggest that the Internet has not - at least in its first two decades of existence - contributed to a global shift towards democracy.

Weidmann, Nils B. "Communication Networks and the Transnational Spread of Ethnic Conflict."

Journal of Peace Research 52(3) 

Theories of conflict diffusion have long argued that domestic conflict spreads from one country to others. One set of mechanisms explaining this relies on material flows across borders that incite violence in neighboring countries. Another set of mechanisms, however, relies on informational flows. Information about ongoing violence elsewhere triggers strategic learning and demonstration effects in sub-national conflict actors which may increase the likelihood that these actors ultimately resort to violence. While the first set of mechanisms can--and has been--assessed using spatial proximity to define connections between countries, this paper provides a test of the second mechanism by analyzing communication flows. The paper shows that the occurrence of ethnic conflict in a country’s main communication partners significantly increases the probability of domestic ethnic violence, and that this effect operates in conjunction with, and is at least as strong as, the spatial contagion effect of conflict in the geographic neighborhood. 

Benitez-Baleato, Suso, Nils B. Weidmann, Petros Gigis, Xenofontas Dimitropoulos, Eduard Glatz and Brian Trammell. "Transparent Estimation of Internet Penetration from Network Observations." 

Proceedings of the 16th Passive and Active Measurement Conference 

The International Telecommunications Union (ITU) and the Organization for Economic Cooperation and Development (OECD) provide Internet penetration statistics, which are collected from official national sources worldwide, and they are widely used to inform policy-makers and researchers about the expansion of digital technologies. Nevertheless, these statistics are derived with methodologies, which are often opaque and inconsistent across countries. Even worse, regimes may have incentives to misreport such statistics. In this work, we make a first attempt to evaluate the consistency of the ITU/OECD Internet penetration statistics with an alternative indicator of Internet penetration, which can be measured with a consistent methodology across countries and relies on public data. We compare, in particular, the ITU and OECD statistics with measurements of the used IPv4 address space across countries and find very high correlations ranging between 0.898 and 0.978 for all years between 2006 and 2010. We also observe that the level of consistency drops for less developed or less democratic countries. Besides, we show that measurements of the used IPv4 address space can serve as a more timely Internet penetration indicator at sub-national granularity, using two large developing countries as case studies. 

Weidmann, Nils B. and Espen Geelmuyden Rød. "Making Uncertainty Explicit: Separating Reports and Events in the Coding of Violence and Contention."

Journal of Peace Research 52(1) 

When coding events from media sources - as the majority of data projects do - different reports may oftentimes contain contradictory information. What do coders make of this? It is up to them to aggregate different reports into one coded event, and to supplement missing information based on other sources or their own background information. If not addressed properly, this may lead to a lack of replicability and to low reliability of the final data product. In this short paper, we present an approach for separating (i) event reports and the information contained in them, and (ii) events, which are based on aggregate information from the reports and constitute the final data product. Our procedure preserves uncertainty arising from multiple reports, and gives the user control over how missing and conflicting information should be dealt with. We illustrate our procedure with data from a current coding project, the Mass Mobilization in Autocracies Database (MMAD).