Joshua D. Kertzer


Joshua D. Kertzer, Resolve in International Politics. Princeton, NJ: Princeton University Press, 2016.

Why do some leaders and segments of the public display remarkable persistence in confrontations in international politics, while others cut and run? The answer given by policymakers, pundits, and political scientists usually relates to issues of resolve. Yet, though we rely on resolve to explain almost every phenomenon in international politics—from prevailing at the bargaining table to winning on the battlefield—we don’t understand what it is, how it works, or where it comes from. Resolve in International Politics draws on a growing body of research in psychology and behavioral economics to explore the foundations of this crucial idea.

I argue that political will is more than just a metaphor or figure of speech: the same traits social scientists and decision-making scholars use to comprehend willpower in our daily lives also shape how we respond to the costs of war and conflict. Combining laboratory and survey experiments with studies of great power military interventions in the postwar era from 1946 to 2003, I show how time and risk preferences, honor orientation, and self-control help explain the ways leaders and members of the public define the situations they face and weigh the trade-offs between the costs of fighting and the costs of backing down.

Offering a novel in-depth look at how willpower functions in international relations, Resolve in International Politics has critical implications for political psychology, public opinion about foreign policy, leaders in military interventions, and international security.

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Peer-reviewed journals

Joshua D. Kertzer and Dustin Tingley, “Political Psychology in International Relations: Beyond the Paradigms”, Annual Review of Political Science, Forthcoming.

Political psychology in international relations has undergone a dramatic transformation in the past two decades, mirroring the broader changes occurring in IR itself. This review essay examines the current state of the field. We begin by offering a data-driven snapshot, analyzing four years of manuscript classifications at a major IR journal to characterize the questions that IR scholars engaged in psychological research are and aren’t investigating. We then emphasize six developments in particular, both present-day growth areas (an increased interest in emotions and hot cognition, the rise of more psychologically-informed work on public opinion, a nascent research tradition we call the "first image reversed", and the rise of neurobiological and evolutionary approaches) and calls for additional scholarship (better integration of the study of mass and elite political behavior, and more psychological work in IPE). Together, they constitute some of the directions in which we see the next generation of scholarship as heading.

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Ryan Brutger and Joshua D. Kertzer, “A Dispositional Theory of Reputation Costs”, International Organization, Forthcoming.

Politicians frequently turn to reputational arguments to bolster support for their proposed foreign policies. Yet despite the prevailing belief that domestic audiences care about reputation, there is very little direct evidence that publics care about reputation costs, and very little understanding of how. We propose a dispositional theory of reputation costs, in which citizens facing ill-defined strategic situations turn to their core predispositions about foreign affairs in order to weigh competing reputational dimensions. Employing a diverse array of methodological tools — from vignette-based survey experiments to automated text analysis — we show that the mass public has a "taste" for reputation, but understands it in fundamentally different ways, with hawks concerned about the negative reputational consequences of inconsistency, and doves equally concerned with the negative reputational consequences of belligerence and interventionism. In illustrating how reputation costs are in our heads, our findings offer both good and bad news for theories of reputation in IR.

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Connor Huff and Joshua D. Kertzer, “How The Public Defines Terrorism”, American Journal of Political Science, Forthcoming.

Every time a major violent act takes place in the US, a public debate erupts as to whether it should be considered terrorism. Political scientists have offered a variety of conceptual frameworks, but have neglected to explore how ordinary citizens understand terrorism, despite the central role the public plays in our understanding of the relationship between terrorism and government action in the wake of violence. We synthesize components of both scholarly definitions and public debates to formulate predictions for how various attributes of incidents affect the likelihood they are perceived as terrorism. Using a conjoint experimental design, we show the importance of the extremity and severity of violence, but also the attributed motivation for the incident, and social categorization of the actor. The findings demonstrate how the language used to describe violent incidents, for which the media has considerable latitude, affects the likelihood the public classifies incidents as terrorism.

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Joshua D. Kertzer and Thomas Zeitzoff, “A Bottom-Up Theory of Public Public Opinion about Foreign Policy”, American Journal of Political Science, 61:3 (July 2017), 543-558.

If public opinion about foreign policy is such an elite-driven process, why does the public often disagree with what elites have to say? We argue here that elite-cuetaking models in IR are both overly pessimistic and unnecessarily restrictive. The public may lack information about the world around them, but it does not lack principles, and information need not only cascade from the top down. We present the results from five survey experiments where we show that cues from social peers are at least as strong as those from political elites. Our theory and results build on a growing number of findings that individuals are embedded in a social context that combines with their general orientations towards foreign policy in shaping responses towards the world around them. Thus, we suggest the public is perhaps better equipped for espousing judgments in foreign affairs than many of our top-down models claim.

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Joshua D. Kertzer, “Resolve, Time, and Risk”, International Organization, 71:S1 (April 2017), S109-S136.

Why do some actors in international politics display remarkable persistence in wartime, while others "cut and run" at the first sign of trouble? I offer a behavioral theory of resolve, suggesting that variation in time and risk preferences can help explain why some actors display more resolve than others. I test the theory experimentally in the context of public opinion about military interventions. The results not only help explain why certain types of costs of war loom larger for certain types of actors, but also shed light onto some of the contributions of the behavioral revolution more broadly.

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Brian C. Rathbun, Joshua D. Kertzer and Mark Paradis, “Homo Diplomaticus: Mixed-Method Evidence of Variation in Strategic Rationality”, International Organization, 71:S1 (April 2017), S33-S60.

Psychology is traditionally used in political science to explain deviations from rationality. Lost in the debate between rationalists and their critics, however, is a sense of whether the kinds of strategic self-interested behavior predicted by these models has psychological microfoundations: what would homo economicus look like in the real world? We argue that strategic rationality has distinct psychological microfoundations characterized by a proself social value orientation and a high level of epistemic motivation, and varies by individuals. Testing our argument in the context of international relations, we employ a laboratory bargaining game and integrate it with in-depth research on German foreign policy-making in the 1920s. We find in both contexts that even among those only interested in maximizing their own egoistic gains, those with greater epistemic motivation are better able to adapt to the strategic situation, most importantly the distribution of power. Our results build a bridge between two approaches often considered to be antithetical to one another.

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Joshua D. Kertzer, “Microfoundations in International Relations,” Conflict Management and Peace Science, 34:1 (January 2017), 81-97.

Many of our theories of international politics rely on microfoundations. In this short note, I suggest that although there has been increasing interest in microfoundations in IR over the past twenty years, the frequency with which the concept is invoked belies a surprising lack of specificity about what microfoundations are, or explicit arguments about why we should study them. I then offer an argument about the value of micro-level approaches to the study of conflict. My claim is not that all theories of IR need to be developed or tested at the micro-level in order to be satisfying, but rather, that many of our theories in IR already rest on lower-level mechanisms — they either leave these assumptions unarticulated, or fail to test them directly. In these circumstances, theorizing and testing micro-level dynamics will be especially helpful. I illustrate my argument using the case of resolve, one of the central explanatory variables in the study of international security. I argue that the absence of microfoundations for resolve is one reason why IR scholars have had difficulties testing whether resolve has the effects we often claim, and sketch out a two-stage research design political scientists can use to study unobservable phenomena.

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Brian C. Rathbun, Joshua D. Kertzer, Jason Reifler, Paul Goren, and Thomas Scotto, “Taking Foreign Policy Personally: Personal Values and Foreign Policy Beliefs”, International Studies Quarterly, 60:1 (March 2016), 234-249.

Previous research has shown that on issues of foreign policy, individuals have “general stances,” “postures,” “dispositions” or “orientations” that inform their beliefs toward more discrete issues in international relations. While these approaches delineate the proximate sources of public opinion in the foreign policy domain, they evade an even more important question: what gives rise to these foreign policy orientations in the first place? Combining an original survey on a nationally representative sample of Americans with Schwartz’s theory of values from political psychology, we show that people take foreign policy personally: the same basic values we know people use to guide choices in their daily lives also travel to the domain of foreign affairs, offering one potential explanation why people who are otherwise uninformed about world politics nonetheless express coherent foreign policy beliefs.

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Joshua D. Kertzer and Ryan Brutger, “Decomposing Audience Costs: Bringing the Audience Back into Audience Cost Theory”, American Journal of Political Science, 60:1 (January 2016), pp. 234-249.

According to a growing tradition in International Relations, one way governments can credibly signal their intentions in foreign policy crises is by creating domestic audience costs: leaders can tie their hands by publicly threatening to use force, since domestic publics punish leaders who say one thing and do another. We argue here that there are actually two logics of audience costs: audiences can punish leaders both for being inconsistent (the traditional audience cost), and for threatening to use force in the first place (a belligerence cost). We employ an experiment that disentangles these two rationales, and turn to a series of dispositional characteristics from political psychology to bring the audience back into audience cost theory. Our results suggest that traditional audience cost experiments may overestimate how much people care about inconsistency, and that the logic of audience costs (and the implications for crisis bargaining) varies considerably with the leader’s constituency.

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Joshua D. Kertzer and Brian C. Rathbun, “Fair is Fair: Social Preferences and Reciprocity in International Politics”, World Politics, 67:4 (October 2015), 613-655.

Behavioral economics has shown that many people often divert from classical assumptions about self-interested behavior: they have social preferences, concerned about issues of fairness and reciprocity. Social psychologists show that these preferences vary across actors, with some displaying more prosocial value orientations than others. Integrating a laboratory bargaining experiment with original archival research on Anglo-French and Franco-German diplomacy in the interwar period, we show how fairness and reciprocity matter in social interactions. Prosocials do not exploit their bargaining leverage to the degree that proselfs do, helping explain why some pairs of actors are better able to avoid bargaining failure than others. In the face of consistent egoism on the part of negotiating partners, however, prosocials engage in negative reciprocity, leading them to adopt the same behaviors as proselfs.

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Daipayan Guha, George M. Ibrahim, Joshua D. Kertzer, and R. Loch Macdonald,“National Socioeconomic Indicators are Associated with Outcomes After Aneurysmal Subarachnoid Hemorrhage: A Hierarchical Mixed-Effects Analysis”, Journal of Neurosurgery, 121:5 (November 2014), 1039-1047.
Joshua D. Kertzer, Kathleen E. Powers, Brian C. Rathbun and Ravi Iyer, “Moral Support: How Moral Values Shape Foreign Policy Attitudes”, Journal of Politics, 76:3 (July 2014), 825-840.

Although classical international relations theorists largely agreed that public opinion about foreign policy is shaped by moral sentiments, public opinion scholars have yet to explore the content of these moral values, and American IR theorists have tended to exclusively associate morality with liberal idealism. Integrating the study of American foreign policy attitudes with Moral Foundations theory from social psychology, we present original survey data showing that the five established moral values in psychology - harm/care, fairness/reciprocity, authority/respect, ingroup/loyalty, and purity/sanctity - are strongly and systematically associated with foreign policy attitudes. The "individualizing" foundations of harm/care and fairness/reciprocity are particularly important drivers of cooperative internationalism, and the "binding" foundations of authority/respect, ingroup/loyalty, and purity/sanctity of militant internationalism. Hawks and hardliners have morals too, just a different set of moral values than the Enlightenment ones emphasized by liberal idealists.

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Joshua D. Kertzer, “Making Sense of Isolationism: Foreign Policy Mood as a Multilevel Phenomenon”, Journal of Politics 75:1 (January 2013), 225-240.

Political scientists have long been interested in the American public's foreign policy mood, but have typically separated the micro-level question (who's more likely to support isolationism?) from the macro-level one (when does isolationism's popularity increase?), even though public opinion is inherently a multilevel phenomenon, as the answers to these two questions interact. Showing how multilevel models can deal with the effects of time rather than just space, I find that both guns and butter drive foreign policy mood, but in different ways. When economic assessments sour, the public's appetite for isolationism increases, but the impact of these individual-level perceptions is constrained by aggregate economic conditions, which are sufficiently salient that they are accessible irrespective of knowledge. The nature of the international security environment, however, predominantly affects foreign policy mood amongst high-knowledge individuals, thereby suggesting that low and high-knowledge individuals' foreign policy views are shaped by different situational cues.

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Joshua D. Kertzer and Kathleen M. McGraw, “Folk Realism: Testing the Microfoundations of Realism in Ordinary Citizens”, International Studies Quarterly 54:2 (June 2012), 245-258.

IR scholars have long debated whether the American public is allergic to realism, which raises the question of how they would "contract" it in the first place. We argue that realism isn't just an IR paradigm, but a belief system, whose relationship with other ideological systems in public opinion has rarely been fully examined. Operationalizing this disposition in ordinary citizens as "folk realism," we investigate its relationship with a variety of personality traits, foreign policy orientations, and political knowledge. We then present the results of a laboratory experiment probing psychological microfoundations for realist theory, manipulating the amount of information subjects have about a foreign policy conflict to determine whether uncertainty leads individuals to adopt more realist views, and whether realists and idealists respond to uncertainty and fear differently.  We find that many of realism's causal mechanisms are conditional on whether subjects already hold realist views, and suggest that emotions like fear may play a larger role in realist theory than many realists have assumed.

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David G. Haglund and Joshua D. Kertzer, “From Geo to Neo: A Speculative Inquiry into the Unusual ‘Geo-Ethnic’ Roots of Neoconservatism in U.S. Foreign Policy”, Geopolitics 13:3 (July 2008), 519-544.
Joshua D. Kertzer, “Seriousness, Grand Strategy, and Paradigm Shifts in the ‘War on Terror’”, International Journal 62:4 (Autumn 2007), 961-979.

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Working papers (selected)

“Tying Hands, Sinking Costs, and Leader Attributes” (with Jonathan Renshon and Keren Yarhi-Milo)

Do costly signals work? Despite their widespread popularity, both hands-tying and sunk-cost signaling have come under criticism, and there's little direct evidence that leaders understand costly signals the way our models tell us they should. We present evidence from a survey experiment fielded on a unique sample of elite decision-makers from the Israeli Knesset. We find that both types of costly signaling are effective in shaping assessments of resolve, for both leaders and the public. However, although theories of signaling tend to assume homogenous audiences, we show that leaders vary significantly in how credible they perceive signals to be, depending on their foreign policy dispositions, rather than their levels of military or political experience. Our results thus encourage IR scholars to more fully bring heterogeneous recipients into our theories of signaling, and point to the important role of dispositional orientations for the study of leaders.

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“Democratic Leaders, Crises and War: Paired Experiments on the Israeli Knesset and Public.” (with Jonathan Renshon and Keren Yarhi-Milo)

IR theorists have focused recently on the implications of regime type for crisis behavior, but any answer to the question of whether democracies are seen as more resolved or effective must account for the fact that, while our theories hinge on the beliefs of leaders, evidence has necessarily come from second-order implications concerning state behavior. We put leaders’ beliefs directly under the microscope, fielding a survey experiment on a unique elite sample of members of the Israeli Knesset. We find that Israeli leaders perceive democracies as more likely to back down in a crisis but more likely to emerge victorious in wars. Paired surveys of the Israeli public allow us to evaluate how similar leaders are to the public they represent, and the mechanisms through which democracy shapes beliefs about conflict, finding support for the notion that experiments on “the average citizen” (at least in some cases) generalize nicely to elites.

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“How do Observers Assess Resolve?” (with Jonathan Renshon and Keren Yarhi-Milo)

What heuristics do observers use to estimate the resolve of others? Although actors go to great lengths to signal or project their resolve to others, there is very little sense in IR as to how observers actually draw these inferences, and many of our theoretical frameworks that try to address this question focus only on a single mechanism at a time, rather than testing their competing predictions or examining how they work in tandem. We innovate by providing a conceptual framework uniting these previously disconnected theories, and employ a conjoint experimental design to test their observable implications, showing how ordinary citizens intuitively carry around many of the core principles of deterrence theory in their heads.

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“The Price of Peace: A Behavioral Approach to Costly Signaling in International Relations” (with Brian Rathbun and Nina Srinivasan Rathbun)

Despite making major contributions to the study of world politics, canonical models of costly signaling in IR tend to assume costly signals speak for themselves: the costliness of a signal is understood to be a function of the signal, not the recipient's perception. Integrating the study of costly signaling in IR with research on motivated skepticism, biased assimilation and asymmetric updating from the study of political psychology, we show that individuals' tendencies to embrace information consistent with their overarching belief systems (and dismiss information consistent with it) has important implications for how costly signals are interpreted. We test our theory in the context of the 2015 Joint Comprehensive Plan of Action (JCPOA) on Iran, combining a survey experiment fielded on members of the mass public in the lead-up to the Iran deal with automated content analysis of speeches about the deal made by US Senators. In both our elite and mass sample, we find that to know whether a signal is considered costly and credible, we need to know something about the orientations of the signal's recipient, and that the most likely to update their beliefs are the ones who already want to do so. Results show that on average recipients of signals adjust their views in the direction expected by canonical signaling models, adding the microfoundations of behavioral data to an approach that typically relies on formal theory or large-N analyses. However, there is also substantial heterogeneity based on biased assimilation.

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“Does Anti-Americanism Exist? Experimental Evidence from France” (with Rick Herrmann)

There are many debates in Washington about anti-Americanism: where it comes from, what implications it has for US foreign policy, and whether it can be eradicated by careful public diplomacy. Yet before we search for a cure for the disease or ascertain how severe its symptoms are, we need to be able to diagnose it in the first place. One reason why anti-Americanism attracts so much attention is that it is often understood as a form of prejudice rather than mere disagreement with American policies. If this is the case, however, we need to be able to differentiate unpopularity from the prejudice believed to be causing it. To do so, we present three novel experiments embedded in a national survey in France in 2009-10, studying anti-Americanism like how political scientists study other forms of prejudice. Our findings counter conventional wisdom in two ways. First, we find relatively little evidence of anti-Americanism in France. Second, a key predictor of anti-Americanism in France is nationalism, but not in the direction some IR scholars might expect: the more attached the French are to their country, the more of a break they give the United States compared to other great powers who behave similarly. The results thus suggest that nationalism and the fostering of a common ingroup are not contradictory forces.

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“Foreign Policy Attitudes as Networks.” (with Kathleen E. Powers)

What’s systemic about foreign policy belief systems? We introduce political scientists to a new — networked — paradigm for political attitudes, and develop a new experimental design that disentangles the directional nature of attitude constraint while leveraging tools from network analysis. We find that established models of foreign policy attitudes make unrealistically strict assumptions about the directionality and uniformity of attitude structure. Specific policy attitudes like the Iraq war play more central roles than our existing theories give them credit for, and the topology of attitude networks varies substantially with individual characteristics like political sophistication.

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“Putting Things in Perspective: Mental Simulation in Experimental Political Science.” (with Jonathan Renshon)

Whether leaders taking the perspective of rivals or allies, student subjects taking the perspective of leaders in lab studies, or citizens taking their own perspective in hypothetical scenarios, most modern IR scholarship draws implicitly on perspective-taking. If our ability to engage in this sort of mental simulation was foolproof, we would have nothing to worry about. Unfortunately, several decades of psychological research suggests that individuals vary tremendously in their ability to do so, and that even when they can manage it, the effects are often negative. Ignoring this critical factor only detracts from our ability to generate and refine theories in IR or test our empirical predictions. We provide a conceptual framework for understanding perspective-taking in IR, focusing on the nature of the “target” (first or third-person) and individuals' inability to adjust from their initial anchor: their own beliefs. Across three experimental studies, we find evidence that perspective-taking exacerbates pre-existing attitudes towards the use of force, making hawks more hawkish and doves more dovish. Perspective-taking thus makes people more like themselves, which raises the prospect that participants are less like themselves in studies that do not take perspective-taking into account.

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Government 1790: American Foreign Policy (Undergraduate) Syllabus
Government 2710: International Relations Field Seminar (Graduate) Syllabus
Government 2749: Political Psychology and International Relations (Graduate)

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I am an Assistant Professor of Government at Harvard University, where I specialize in the intersection of international security, foreign policy, political psychology, and quantitative and experimental methods.

My book, Resolve in International Politics, was published in 2016 by Princeton University Press, and received the 2017 Alexander L George Award from the International Society of Political Psychology for the best book published in the field of political psychology. My research has also appeared in a number of journals, including the American Journal of Political Science, Annual Review of Political Science, Conflict Management and Peace Science, International Organization, International Studies Quarterly, the Journal of Politics, and World Politics.

It has also received a variety of other awards, including the 2014 CGS/ProQuest Distinguished Dissertation Award from the Council of Graduate Schools for the best dissertation in the social sciences, the American Political Science Association's 2014 Helen Dwight Reid Award for the best dissertation in international relations, law and politics, the 2014 Kenneth N. Waltz award for the best dissertation in the field of international security and arms control, and the Peace Science Society's 2014 Walter Isard Award for the best dissertation in peace science. It has also been featured on The Colbert Report, Chelsea Lately, and Real Time with Bill Maher — briefly making (some of) my students think I'm cooler than I actually am.

I graduated with a PhD in Political Science from The Ohio State University in August 2013. Before coming to Harvard, I was a Dartmouth Fellow in US Foreign Policy and International Security at the Dickey Center for International Understanding at Dartmouth College. In 2016-17, I was a Visiting Associate Research Scholar at the Niehaus Center for Globalization and Governance at Princeton University.