Peer-Reviewed Publications

The Credibility of Public and Private Threats: A Document-Based Approach

(with Azusa Katagiri. In APSR. Supplementary materials.)

Crisis bargaining literature has predominantly used formal and qualitative methods to debate the relative efficacy of actions, public words, and private words. These approaches have overlooked the reality that policymakers are bombarded with information and struggle to adduce actual signals from endless noise. Events are therefore more effective than any diplomatic communication in shaping elites' perceptions. Moreover, while ostensibly "costless," private messages provide a more precise communication channel than public and "costly" pronouncements. Over 18,000 documents from the Berlin Crisis of 1958-1963 reflecting private statements, public statements, and White House evaluations of Soviet resolve are digitized and processed using statistical learning techniques to evaluate these claims. Results indicate that costly actions have greater influence on White House beliefs than either public or private statements; that public statements are noisier than private statements; and that private statements have a larger effect on evaluations of resolve than public statements. 

Working Papers

Interstate War Battle Dataset (1823-2003)

(latest draft)

Extant scholarship on interstate war and conflict resolution has predominantly utilized formal models, case studies, and statistical works using wars as the unit of analysis to assess the impact of battlefield activity on the duration and termination of hostilities. As such, longstanding views of war have not been tested systematically using intra-conflict measures, and deeper studies of within-war dynamics have also been hampered. I address these gaps by creating and introducing the Interstate War Battle (IWB) dataset, which captures the outcomes and dates of 1,708 battles across 94 interstate wars between 1823 and 2003. This paper describes the historical sources used to create these data; outlines definitions of battle outcomes and dates; and provides descriptive statistics for the basic battle data and several daily-level measures constructed using these data. I then use the data to test the implications of two major theoretical perspectives on conflict termination: the informational view, which emphasizes convergence in beliefs through battlefield activity; and Zartman's ripeness theory, which highlights costly stalemates in fighting. Using competing risk models, I find strong evidence for informational views and little support for ripeness theory: New battlefield outcomes promote negotiated settlements, while battlefield stagnation undermines both diplomatic and military means of ending conflict. The IWB dataset has significant implications, highlights future research topics, and motivates a renewed research agenda on the empirical study of conflict.

Talking while Fighting: Understanding the Role of Wartime Negotiation

(latest draft)

Contemporary studies of conflict have adopted approaches that minimize the importance of negotiation during war or treat it as a constant and mechanical activity. This is tightly related to the lack of systematic data that tracks and illustrates the complex nature of wartime diplomacy. I address these issues by creating and exploring a new daily-level dataset of negotiations in all interstate wars from 1816 to present. I find strong indications that post-1945 wars feature more frequent negotiations and that these negotiations are far less predictive of war termination. Evidence suggests that increased international pressures for peace and stability after World War II, especially emanating from nuclear weapons and international alliances, account for this trend. These original data and insights establish a dynamic research agenda that enables a more policy-relevant study of conflict management, highlights a historical angle to conflict resolution, and speaks to the utility of viewing diplomacy an essential dimension to understanding war.

Negotiation as an Instrument of War

(latest draft)

What role do negotiations play in the trajectory and termination of interstate wars? Extant scholarship has largely treated negotiations as an activity that mirrors outcomes from fighting. This view of negotiations as a simple reflection of the battlefield is not well-supported by historical readings or empirical patterns of intra-war diplomacy, particularly in wars after 1945. I present an alternative view of negotiations as being instrumental. Diplomatic bargaining not only occurs in response to battlefield outcomes, but is also used as a tool that allows beleaguered war targets to stall for time and mitigate the war initiator's strategic first-mover advantage on the battlefield. Using two new daily-level datasets of battles and diplomatic activity, I show that negotiations in post-1945 wars extend conflict when the war initiator has an advantage in fighting, dampen the intensity of active hostilities, and are associated with reversals of fortune favoring the war target. This framework of instrumental negotiations shows that the effect of intra-war diplomacy is conditional on the state of hostilities, and has substantial implications on our understanding of war termination and conflict resolution.

How does battlefield activity relate to belligerents' interest in seeking a resolution to conflict? Extant studies of intra-war dynamics, few in number, treat wartime costs as exogenous information that promotes belligerents' interest in peace. Moreover, interest in peace is captured using war termination, without finer-grained measures of intra-conflict bargaining behavior. I argue that costs are endogenous to belligerents' effort to gain or defend objectives that they believe are vital to prospective bargaining. Therefore, costs reflect an objective's strategic importance. Using text-based, machine learning, and statistical methods on daily military operations reports and negotiation transcripts from the Korean War, I show that military gains and losses involving important strategic objectives are linked to decreased interest in settlement. Moving past contemporary literature, this study disentangles battlefield costs and outcomes, emphasizes the importance of endogenizing the costs of conflict, and provides a framework for applying statistical learning methods to the analysis of war.

Endogenizing the Costs of Conflict: A Text-Based Application to the Korean War

(latest draft)

Looking for Trouble: Analyzing Search Engine Data during International Crises

(with Lizhi Liu; latest draft)

Many theories of crisis bargaining and conflict are predicated on the idea that actors constantly observe and process information obtained from words and deeds. However, very few studies have explicitly evaluated whether individuals inform themselves about developments in the midst of crisis, and little thought has been put into the specific mechanisms that would motivate such behavior. This paper uses search engine data from Baidu (China's largest service) to address these issues through the lens of the current South China Sea dispute. Baidu search data provides unique access to daily, province-level, and unbiased statistics on behavior in an illiberal and autocratic country. We use this resource to show that citizens indeed seek information in response to crisis events, and that these patterns of information seeking are best explained as attempts to resolve uncertainty and anxiety that the South China Sea dispute and its related events imply.

Identifying Threats: Using Machine Learning in International Relations

(with Azusa Katagiri; latest draft)

International relations (IR) scholars have always placed great emphasis on the importance of threats in explaining interstate behavior--especially in the midst of crises. However, few studies have evaluated threats in a systematic way, mainly due to lack of substantively and methodologically sound data. Our study uses machine learning techniques on digitized U.S. diplomatic documents from the Foreign Relations of the United States 1945-1980 collection. We utilize a statistical learning model to classify documents during the Cold War as expressing perceived threat or not, and then analyze this using event data on the United States and Soviet Union. Time-series analysis shows that threats are perceived prior to actually threatening events, and reveal far greater detail on interstate reciprocity. We conclude by suggesting that IR’s current empirical approaches to threats may be problematic, and that our methods may lay the foundations for an ambitious research agenda that can test many long-standing theories in IR.

Despite general academic consensus on terrorism being a strategic and communicative act, most extant work has only analyzed these features in relation to the actual attack itself. However, much of the communicative and strategic weight may come from a public claim of responsibility for the attack (or lack thereof). A terrorist attack is fundamentally an intimidating costly signal that foments uncertainty; claims of credit can naturally be viewed as a manner in which to augment the costliness and uncertainty of this base signal. Using this insight, I develop a series of hypotheses to test several well-established and  costly qualitative theoretical arguments in the literature. Focus is placed on Kydd and Walter’s (2006) important work on extremists’ strategies. Using econometric analysis on the Global Terrorism Database and case studies of three extremist organizations in Pakistan, I find that credit-claiming is indeed consistent with these strategies: While a dominant strategy of intimidation keeps claim rates low, extremists are more likely to claim responsibility for attacks that involve high costs (suicide and casualties), institutionally constrained states (democracy), and competitive environments. Attempts to sabotage political
moderation serve to suppress claims. Moreover, groups with limited and specific aims, such as separatist organizations, are likely to have a higher claim rate than organizations with more sweeping and amorphous objectives. These findings not only tap into a largely overlooked dimension of violent political communication, but function as a useful test of extant theories in the terrorism literature that have thus far been evaluated using very small-N analysis.

Taking Responsibility: When and Why Terrorists Claim Credit for Attacks

(latest draft)

Explaining Military Relapse

(with Jonathan Chu; please do not cite without authors' permission; latest draft)

Renewed interest in authoritarian rule has sparked a groundswell of literature on regime change and consolidation. Most of this work does not explicitly mention or address the tendency for military regimes to transition to multi-party civilian rule, only to quickly revert back to military control. We define this phenomenon in which a military regime transfers power to civilian leaders only to retake power \military relapse." By integrating insights from contemporary work on autocracies with older literature on the military and civil-military relations, we develop a theory to explain military relapses. We find that characteristics unique to the military motivate their exit from power. In establishing the civilian regime to follow, the balance between civilian and military prerogatives is determined by the relative levels of unity within each party, which also influences their mutual levels of trust. These factors, combined with the potential costs for the military of reclaiming power, explain the likelihood of and trends in military relapse. Case studies of multiple civilian-military interactions in Myanmar and Peru support this theory

Additional research

2017. Report, Empirical Studies of Conflict Project, Princeton University.

Click here for the most recent version of the report.

Understanding Risk and Resilience to Violent Conflicts

(with Manu Singh, Jacob N. Shapiro, and Benjamin Crisman)

A regime dataset that classifies all country-years from 1950 to 2012 by different forms of autocratic rule. Introduces a novel form of measuring personalist rule across all autocracies and offers several corrections to extant regime classification data.

Click here for site with data and codebook.

Autocracies of the World, 1950-2012

(with Beatriz Magaloni and Jonathan Chu)