Joseph J. Ruggiero

I am an assistant professor at the University of Virginia, where I study topics in international relations and political economy. My work uses game theory and quantitative methods to understand strategic political interactions. I am especially interested in the role of interstate alliances, economic interdependence, and diplomacy in war. I completed my Ph.D. at Princeton University in 2024 and was previously a postdoc at Stanford University.

Publications

• “Competitive Diplomacy in Bargaining and War.” Forthcoming, American Journal of Political Science. [article] [manuscript]

  Abstract

  War is often viewed as a bargaining problem. However, prior to bargaining, countries can vie for leverage by expending effort on diplomacy. This article presents a dynamic model of conflict where agenda-setting power is endogenous to pre-bargaining diplomatic competition. The ability to compete for leverage generates a new channel through which the nature of potential war affects the quality of peace. First, costs of war grow the bargaining surplus, fueling the battle for leverage and reducing welfare even if war never occurs on the path of play. Second, competitive diplomacy erodes the gains from peace, making it possible that war is relatively efficient. An extension of the model finds that frictions to cooperation create a risk of costly delay but also protect against erosion of the surplus. Moreover, I find that reliable deals avert “efficient” wars but introduce a trade-off between welfare and timely settlement.




• “Preventive War and Sovereign Debt” with Colin Krainin, Kristopher W. Ramsay, and Bella Wang. Conflict Management and Peace Science, 39(5), 487-519, 2022. [article] [supplementary appendix] [replication code]

  Abstract

  The preventive motive for war arises because states cannot commit to limit the use of their growing power. This commitment problem can lead to war when there are not enough resources available today to compensate the declining state for their expected losses. In this article, we show how capital markets affect preventive war incentives by introducing a profit-maximizing bond market to the canonical bargaining model of war. We find that the nature of the power shift and fundamentals of the market for debt interact to determine when a preventive motive is more likely to lead to war. Two main results show that (1) less probable but more extreme power shifts are most dangerous and (2) unlike the direct effect of interest rates on the cost of war, higher interest on sovereign debt makes war more likely. We present evidence for the latter effect by extending Lemke's (2003) study of preventive war for major-power dyads between 1816 and 1992.

Working papers

• “What Makes a World War? A Structural Analysis of Integration.” [manuscript]

  Awards:

  1. “Best APSA Paper” by APSA Formal Theory Section
  2. “Best Graduate Student Paper” by the Formal Models of Conflict Conference
  Abstract

  The size of a war, as well as the incentive to start one, depends on expectations about which countries will join. These expectations are in turn shaped by the structure of political alignments and integration. I propose a model of conflict that accounts for these factors and, using data on international disputes from 1816-2014, I use structural estimation techniques to connect theory with data. I then estimate the effect of integration on the incentives for conflict. My results suggest that integration makes wars smaller but more likely—integration pacifies potential joiners, reducing the scale of war but consequently triggering more attacks due to an expectation for less opposition. Moreover, I identify a strong correlation between power inequality and the expected size of war in equilibrium, driven largely by bandwagoning from the stronger side. Finally, the model facilitates counterfactual experiments, which I demonstrate by considering a number of potential disputes between China and Taiwan after the Cold War.




• “Diversionary Escalation: Theory and Evidence from Eastern Ukraine” with Natalie Ayers, Christopher Blair, Austin Wright, and Konstantin Sonin. [manuscript]

  Abstract

  When leaders face threats to their authority, engaging in violence may provide a means of diverting public attention away from domestic grievances. Quantitative evidence of diversionary behavior has been challenging to obtain. In this paper, we present a formal theory and empirical evidence that diversionary motives can explain periodic intensification of combat during proxy war. Our theory considers a regime that may engage in diversion directly or by proxy as a tactic to forestall public opposition and domestic unrest. Using a new dataset of 2 million conflict incidents during the Ukrainian separatist conflict from 2015-2022, obtained from the Organization for Security and Co-operation in Europe's (OSCE) Special Monitoring Mission to Ukraine, we find evidence that the Russian government strategically employed proxy-initiated violence to divert attention from domestic unrest and opposition-led protest. Anti-regime protests in Russia correspond with an increase in ceasefire violations in Donbas. This effect was driven by large-scale, escalatory combat. Using data from Russian media, we also find a positive link between opposition protest and inflammatory anti-Ukrainian coverage, complementary to battlefield proxy escalation.

Work in progress

• “Battlefield Information Manipulation” with Christopher Blair.




• “Loyalty and Expertise in Foreign Policy Advising” with Matias Iaryczower and Matt Malis.




• “Propping Up Allies With Uncertain Prospects” with Kristopher W. Ramsay.