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Reputation and International Cooperation: Sovereign Debt across Three Centuries. Princeton, NJ: Princeton University Press, 2007.

The following summary is from the publisher's website:

How does cooperation emerge in a condition of international anarchy? Michael Tomz sheds new light on this fundamental question through a study of international debt across three centuries. Tomz develops a reputational theory of cooperation between sovereign governments and foreign investors. He explains how governments acquire reputations in the eyes of investors, and argues that concerns about reputation sustain international lending and repayment.

Tomz's theory generates novel predictions about the dynamics of cooperation: how investors treat first-time borrowers, how access to credit evolves as debtors become more seasoned, and how countries ascend and descend the reputational ladder by acting contrary to investors' expectations. Tomz systematically tests his theory and the leading alternatives across three centuries of financial history. His remarkable data, gathered from archives in nine countries, cover all sovereign borrowers. He deftly combines statistical methods, case studies, and content analysis to scrutinize theories from as many angles as possible.

Tomz finds strong support for his reputational theory while challenging prevailing views about sovereign debt. His pathbreaking study shows that, across the centuries, reputations have guided lending and repayment in consistent ways. Moreover, Tomz uncovers surprisingly little evidence of punitive enforcement strategies. Creditors have not compelled borrowers to repay by threatening military retaliation, imposing trade sanctions, or colluding to deprive defaulters of future loans. He concludes by highlighting the implications of his reputational logic for areas beyond sovereign debt, further advancing our understanding of the puzzle of cooperation under anarchy.

For a longer synopsis of the book, click here. The book is available from Princeton University Press and


Modern Political Economy and Latin America: Theory and Policy (edited with Jeffry Frieden and Manuel Pastor). Boulder: Westview Press, 2000.

A collection of readings on the relationship between politics and economics in developing countries, with a special emphasis on Latin America. The book contains 35 essays that show students how modern political-economic tools can explain market failures and government policy in areas such as international trade and capital flows, economic growth and business cycles, income inequality, gender relations and the environment. The introduction provides an analytical framework; sections at the beginning of each chapter summarize the articles and discuss their relationship to the broader study of political economy. Modern Political Economy and Latin America is intended for use in undergraduate and graduate-level courses in political science and economics.

The book is available from


The Effects of Naming and Shaming on Public Support for Compliance with International Agreements: An Experimental Analysis of the Paris Agreement (with Dustin Tingley). International Organization 76, no. 2 (Spring 2022): 445-68.

How does naming and shaming affect public support for compliance with international agreements? We investigated this question by conducting survey experiments about the Paris Agreement, which relies on social pressure for enforcement. Our experiments, administered to national samples in the United States, produced three sets of findings. First, shaming by foreign countries shifted domestic public opinion in favor of compliance, increasing the political incentive to honor the Paris Agreement. Second, the effects of shaming varied with the behavior of the target. Shaming was more effective against partial compliers than against targets that took no action or honored their obligations completely. Moreover, even partial compliers managed to reduce the effects of shaming through the strategic use of counter-rhetoric. Third, identity moderated responses to shaming. Shaming by allies was not significantly more effective than shaming by non-allies, but Democrats were more receptive to shaming than Republicans. Overall, our experiments expose both the power and the limits of shaming as a strategy for enforcing the Paris Agreement. At the same time, they advance our understanding of the most significant environmental problem facing the planet. Click here for online appendix, and here for the replication files.


Military Alliances and Public Support for War  (with Jessica Weeks). International Studies Quarterly, Volume 65, Issue 3, September 2021, Pages 811–824.

How do military alliances affect public support for war to defend victims of aggression? We offer the first experimental evidence on this fundamental question. Our experiments revealed that alliance commitments greatly increased the American public’s willingness to intervene abroad. Alliances shaped public opinion by increasing public fears about the reputational costs of nonintervention, and by heightening the perceived moral obligation to intervene out of concerns for fairness and loyalty. Finally, although alliances swayed public opinion across a wide range of circumstances, they made the biggest difference when the costs of intervention were high, the stakes of intervention were low, and the country needing aid was not a democracy. Thus, alliances can create pressure for war even when honoring the commitment would be extremely inconvenient, which could help explain why democratic allies tend to be so reliable. These findings shed new light on the consequences of alliances and other international legal commitments, the role of morality in foreign policy, and ongoing debates about domestic audience costs. Click here for online appendix, and here for the replication files.


Public Opinion and Foreign Electoral Intervention (with Jessica Weeks). American Political Science Review 114, no. 3 (August 2020): 856–73.

Foreign electoral intervention is an increasingly important tool for influencing politics in other countries, yet we know little about when citizens would tolerate foreign efforts to sway elections and when they would condemn them. In this paper, we use experiments to study American public reactions to revelations of foreign electoral intervention. We find that even modest forms of intervention polarize the public along partisan lines. Americans are more likely to condemn foreign involvement, lose faith in democracy, and seek retaliation when a foreign power sides with the opposition, than when a foreign power aids their own party. At the same time, Americans reject military responses to electoral attacks on the United States, even when their own political party is targeted. Our findings suggest that electoral interference can divide and weaken an adversary without provoking the level of public demand for retaliation typically triggered by conventional military attacks. Click here for online appendix.


Public Opinion and Decisions about Military Force in Democracies (with Jessica Weeks and Keren Yarhi-Milo). International Organization 74, no. 1 (Winter 2020): 119–43.

Many theories of international relations assume that public opinion exerts a powerful effect on foreign policy in democracies. Previous research, based on observational data, has reached conflicting conclusions about this foundational assumption. In this research note, we use experiments to examine two mechanisms—responsiveness and selection—through which opinion could shape decisions about the use of military force. We tested responsiveness by asking members of the Israeli parliament to consider a crisis in which we randomized information about public opinion. Parliamentarians were more willing to use military force when the public was in favor, and believed that contravening public opinion would entail heavy political costs. We tested selection by asking citizens in Israel and the U.S. to evaluate parties/candidates, which varied randomly on many dimensions. In both countries, foreign policy proved as electorally significant as economic and religious policy, and far more consequential than non-policy considerations such as gender, race, and experience. Overall, our experiments in two important democracies imply that citizens can affect policy by incentivizing incumbents and shaping who gets elected. Click here for the online appendix.


Human Rights and Public Support for War (with Jessica Weeks). Journal of Politics 82, no. 1 (January 2020): 182–94.

One of the most important themes in international relations is the relationship between domestic politics and interstate conflict. In this article, we use experiments to study how the human rights practices of foreign adversaries affect domestic public support for war. Our experiments, embedded in surveys in the United States and the United Kingdom, reveal several important findings. First, citizens are much less willing to attack a country that respects human rights than a country that violates them, even when the dispute concerns military security rather than humanitarian intervention. Second, human rights affect support for war primarily by changing perceptions about threat and morality. Citizens are more likely to view human rights violators as threatening, and have fewer moral qualms about fighting such countries. Our findings shed new light on the politics of war in democracies, and may provide behavioral foundations for peace among human-rights-respecting states. Click here for the online appendix, and here for replication files.


International Commitments and Domestic Opinion: The Effect of the Paris Agreement on Public Support for Policies to Address Climate Change (with Dustin Tingley), Environmental Politics 29, no. 7 (2020): 1135-1156.

How might voluntary international commitments affect domestic support for costly policies to address climate change? We investigated this question by studying the effect of the Paris Agreement on the American public. Our survey experiments supported three conclusions. First, voluntary international commitments shaped public opinion; public support for emissions control policies was much higher in scenarios where the U.S. government had joined the Paris Agreement than in scenarios where it had not. This effect held not only in the population as a whole, but also by political party. Second, although international agreements were influential in general, they were most effective at changing majority opinion about policies with intermediate costs. Finally, our experiments exposed the dangers of promising too much (overpledging) or too little (underpledging). These findings have important implications for the design and consequences of international agreements. Click here for the online appendix.


Does Private Regulation Preempt Public Regulation? (with Neil Malhotra and Benoit Monin). American Political Science Review 113, no. 1 (February 2019): 19–37.

Previous research has emphasized corporate lobbying as a pathway through which businesses influence government policy. This paper examines a less studied mode of influence: private regulation, defined as voluntary efforts by firms to restrain their own behavior. We argue that firms can use modest private regulations as a political strategy to preempt more stringent public regulations. To test this hypothesis, we administered experiments to three groups that demand environmental regulations: voters, activists, and government officials. Our experiments revealed how each group responded to voluntary environmental programs (VEPs) by firms. Relatively modest VEPs dissuaded all three groups from seeking more draconian government regulations, a finding with important implications for social welfare. We observed these effects most strongly when all companies within an industry joined the voluntary effort. Our study documents an understudied source of corporate power, while also exposing the limits of private regulation as a strategy for influencing government policy. Click here for the online appendix, and here for replication files.


Why Don’t Trade Preferences Reflect Economic Self-Interest? (with Sungmin Rho). International Organization 72, no. S1 (2017): S85–S108.

The dominant approach to the study of international political economy assumes that the policy preferences of individuals and groups reflect economic self-interest. Recent research has called this assumption into question by suggesting that voters do not have economically self-interested preferences about trade policy. We investigate one potential explanation for this puzzling finding: economic ignorance. We show that most voters do not understand the economic consequences of protectionism. We then use experiments to study how voters would respond if they had more information about how trade barriers affect the distribution of income. We find that distributional cues generate two opposing effects: they make people more likely to express self-serving policy preferences, but they also make people more sensitive to the interests of others. In our study both reactions were evident, but selfish responses outweighed altruistic ones. Thus, if people knew more about the distributional effects of trade, the correlation between personal interests and policy preferences would tighten. By showing how the explanatory power of economic self-interest depends on beliefs about causality, this research provides a foundation for more realistic, behaviorally informed theories of international political economy. Supplementary materials are available here.


Conditional Cooperation and Climate Change (with Dustin Tingley). Comparative Political Studies 47, no. 3 (March 2014): 344–68.

It is widely believed that international cooperation can arise through strategies of reciprocity. In this paper, we investigate whether citizens in the United States and twenty-five other countries support reciprocity to deal with climate change. We find little public enthusiasm for intrinsic reciprocity, in which countries restrain their consumption of fossil fuels if and only if other countries do the same. In contrast, we find significant support for extrinsic reciprocity, in which countries enforce cooperation by linking issues. Citizens support economic sanctions against polluters and are willing to shame them in international forums, especially when the polluters are violating a treaty. Cooperation could, therefore, emerge from efforts to link climate with other issues and to embed climate commitments in international law.


Public Opinion and the Democratic Peace (with Jessica Weeks). American Political Science Review 107, no. 4 (November 2013): 849–865.

One of the most striking findings in political science is the democratic peace: the absence of war between democracies. Some authors attempt to explain this phenomenon by highlighting the role of public opinion. They observe that democratic leaders are beholden to voters and argue that voters oppose war because of its human and financial costs. This logic predicts that democracies should behave peacefully in general, but history shows that democracies avoid war primarily in their relations with other democracies. In this article we investigate not whether democratic publics are averse to war in general, but whether they are especially reluctant to fight other democracies. We embedded experiments in public opinion polls in the United States and the United Kingdom and found that individuals are substantially less supportive of military strikes against democracies than against otherwise identical autocracies. Moreover, our experiments suggest that shared democracy pacifies the public primarily by changing perceptions of threat and morality, not by raising expectations of costs or failure. These findings shed light on a debate of enduring importance to scholars and policy makers. Online appendix is here.


Empirical Research on Sovereign Debt and Default (with Mark Wright). Annual Review of Economics 5 (May 2013): 247–272.

In this essay we review the empirical literature about sovereign debt and default. As we survey the work of economists, historians, and political scientists, we also emphasize parallel developments by theorists and recommend steps to improve the correspondence between theory and data.


International Finance. In Handbook of International Relations, 2nd ed., eds. Walter Carlsnaes, Thomas Risse, and Beth Simmmons, pp. 692–719. New York: Sage, 2012.

This article critically examines recent research about capital controls and sovereign debt. First, I describe regulations on international investment and consider how three factors—economic ideas, international force, and domestic pressures—have shaped government decisions about capital controls. Second, I analyze how both international and domestic forces have contributed to cooperation between governments and foreign lenders.


Sovereign Theft: Theory and Evidence about Sovereign Default and Expropriation (with Mark Wright). In The Natural Resources Trap: Private Investment without Public Commitment, eds. William Hogan and Federico Sturzenegger, pp. 69–110. Cambridge, MA: MIT Press, 2010.

This paper examines two major risks to foreign investors: default on sovereign debt and expropriation of foreign direct investment, which we refer to collectively as ``sovereign theft.'' Using a series of formal models, we analyze how the incentives to engage in sovereign theft vary with the state of the economy, the risk aversion of political leaders, and the nature of punishments for default and expropriation. We then document patterns of sovereign theft and foreign investment across much of the twentieth century. Our research, based on a new data set, reveals a striking asynchronicity: defaults and expropriations have occurred in alternating, rather than coincident, waves. Our findings shed new light on the possibility of reputation spillovers across issues, and on cooperation and conflict in the international economy.

A replication dataset (Stata format) is available here.


The Electoral Implications of Candidate Ambiguity (with Robert Van Houweling). American Political Science Review 103, no. 1 (February 2009): 83–98.

Candidates often make ambiguous statements about the policies they intend to pursue. In theory, ambiguity affects how voters make choices and who wins elections. In practice, measurement and endogeneity problems have impeded empirical research about the consequences of ambiguity. We conducted survey experiments that overcame these obstacles by manipulating a common form of ambiguity: the imprecision of candidate positions. Our data show that, on average, ambiguity does not repel and may, in fact, attract voters. In nonpartisan settings, voters who have neutral or positive attitudes toward risk, or who feel uncertain about their own policy preferences, tend to embrace ambiguity. In partisan settings, voters respond even more positively to ambiguity; they optimistically perceive the locations of ambiguous candidates from their own party without pessimistically perceiving the locations of vague candidates from the opposition. We further find, through analysis of two additional new data sets, that candidates often take—and voters frequently perceive—ambiguous positions like the ones in our experiments. The pervasive use of ambiguity in campaigns fits with our experimental finding that ambiguity can be a winning strategy, especially in partisan elections.


The Foundations of Domestic Audience Costs: Attitudes, Expectations, and Institutions. In Kitai, Seido, Gurobaru-shakai (Expectations, Institutions, and Global Society), eds. Masaru Kohno and Aiji Tanaka, pp. 85–97. Tokyo: Keiso-Shobo, 2009. The final version in Japanese is here.

This paper examines three themes—attitudes, expectations, and institutions—that are important for understanding audience costs. First, the paper examines the attitudes citizens express about leaders who make threats and subsequently renege. Second, it considers how leaders expect their own citizens to respond to such patterns of behavior. Third, it investigates whether audience costs are perceived to be greater in some institutional settings than in others. Experiments, embedded in interviews with voters and policymakers, support three conclusions. First, citizens disparage leaders who escalate crises and then back down. Second, leaders expect this negative reaction from citizens. Members of the British House of Commons were far more likely to anticipate a public backlash when the prime minister climbed down from a threat, than when the prime minister stayed out of a conflict completely. This finding is important because audience costs affect credibility only insofar as political leaders anticipate the costs. Third, domestic political institutions are relevant for audience costs, but the simple distinction between democratic and autocratic regimes is less salient than scholars typically assume. When judging threats by other nations, British MPs believed the domestic penalty for backing down in a military confrontation would be just as high in autocracies as in democracies.


Candidate Positioning and Voter Choice (with Robert Van Houweling). American Political Science Review 102, no. 3 (August 2008): 303–18.

This article examines a fundamental aspect of democracy: the relationship between the policy positions of candidates and the choices of voters. Researchers have suggested three criteria—proximity, direction, and discounting—by which voters might judge candidates’ policy positions. More than 50 peer-reviewed articles, employing data from more than 20 countries, have attempted to adjudicate among these theories. We explain why existing data and methods are insufficient to estimate the prevalence of these criteria in the electorate. We then formally derive an exhaustive set of critical tests: situations in which the criteria predict different vote choices. Finally, through survey experiments concerning health care policy, we administer the tests to a nationally representative sample. We find that proximity voting is about twice as common as discounting and four times as common as directional voting. Furthermore, discounting is most prevalent among ideological centrists and nonpartisans, who make sophisticated judgments that help align policy with their preferences. These findings demonstrate the promise of combining formal theory and experiments to answer previously intractable questions about democracy. (Note: An earlier version of this paper was called "The Microfoundations of Issue Voting.")

A complete replication archive (computer code, data, and output) is available here.


Domestic Audience Costs in International Relations: An Experimental ApproachInternational Organization 61, no. 4 (Fall 2007): 821–40.

What makes international threats credible? Recent theories point to domestic audience costs: the domestic price a leader would pay for making foreign threats and then backing down. This article provides the first direct evidence of audience costs. The analysis, based on experiments embedded in public opinion surveys, shows that audience costs exist across a wide range of conditions and increase with the level of escalation. The costs are evident throughout the population, and especially among politically active citizens who have the greatest potential to shape government policy. Finally, preliminary evidence suggests that audience costs arise because citizens care about the international reputation of the country or leader. These findings help identify how, and under what conditions, domestic audiences make commitments credible. At the same time, they demonstrate the promise of using experiments to answer previously intractable questions in the field of international relations. (For a longer version of the paper, click here.)

A replication dataset (Stata format) is available here. Replication files are also available from the website of Time-Sharing Experiments in the Social Sciences.


Do We Really Know That the WTO Increases Trade? Comment (with Judith Goldstein and Douglas Rivers). American Economic Review 97, no. 5 (December 2007): 2005–18.

Recent research concludes that membership in the GATT/WTO had no effect on foreign trade. By mistakenly classifying many countries as outsiders, even though they had rights and obligations under the agreement, this work systematically underestimates the effect of GATT. We correct the downward bias in previous estimates. Our analyses show that GATT substantially increased trade, and that its effects were relatively stable across countries and over time.

For coverage in the Economist, click here. An earlier version of this paper was entitled "Membership Has Its Privileges: The Impact of the GATT on International Trade."

A complete replication archive (computer code, data, and output) is available here. If you would like the final dataset without associated computer code and output files, download this archive instead.


Institutions in International Relations: Understanding the Effects of the GATT and the WTO on World Trade (with Judith Goldstein and Douglas Rivers). International Organization 61 (Winter 2007): 37–67.

The General Agreement on Tariffs and Trade (GATT) and the World Trade Organization (WTO) have been touted as premier examples of international institutions, but few studies have offered empirical proof. This article comprehensively evaluates the effects of the GATT/WTO and other trade agreements since World War II. Our analysis is organized around two factors: institutional standing and institutional embeddedness. We show that many countries had rights and obligations, or institutional standing, in the GATT/WTO even though they were not formal members of the agreement. We also expand the analysis to include a range of other commercial agreements that were embedded with the GATT/WTO. Using data on dyadic trade since 1946, we demonstrate that the GATT/WTO substantially increased trade for countries with institutional standing, and that other agreements had similarly positive effects. Moreover, our evidence suggests that international trade agreements have complemented, rather than undercut, each other.

A replication archive (computer code, data, and output) is available here.


Do Countries Default in Bad Times? (with Mark Wright). Journal of the European Economic Association 5, no. 2-3 (May 2007): 352–60.

This paper uses a new dataset to study the relationship between economic output and sovereign default for the period 1820-2004. We find a negative but surprisingly weak relationship between economic output in the borrowing country and default on loans from private foreign creditors. Throughout history, countries have indeed defaulted during bad times (when output was relatively low), but they have also suspended payments when the domestic economy was favorable, and they have maintained debt service in the face of adverse shocks. This constitutes a puzzle for standard theories of international debt, which predict a much tighter negative relationship as default provides partial insurance against declines in output. (For a longer version of the paper, click here.)


How Does Voting Equipment Affect the Racial Gap in Voided Ballots? (with Robert Van Houweling). American Journal of Political Science 47, no. 1 (January 2003): 46–60.

An accumulating body of research suggests that African Americans cast invalid ballots at a higher rate than whites. Our analysis of a unique precinct-level dataset from South Carolina and Louisiana shows that the black-white gap in voided ballots depends crucially on the voting equipment people use. In areas with punch cards or optically scanned ballots, the black-white gap ranged from four to six percentage points. Lever and electronic machines, which prohibit overvoting and make undervoting more transparent and correctible, cut the discrepancy by a factor of ten. Judging from exit polls and opinion surveys, much of the remaining difference could be due to intentional undervoting, which African Americans profess to practice at a slightly higher rate than whites. In any case, the use of appropriate voting technologies can virtually eliminate the black-white disparity in invalid ballots.

We have also written a research note, Proxy Variables and the Racial Gap in Voided Ballots. In the note we discuss the consequences of using imperfect proxies, such as the nonwhite proportion of either registered voters or the general population, to characterize those who actually went to the polls. We argue that when the assumptions for unbiased ecological regression are otherwise satisfied, the use of proxies introduces nonrandom measurement error that depresses estimates of African American and white invalidation, as well as the difference between the two rates. Our AJPS article avoids these problems by employing direct measures of turnout by race.


An Easy and Accurate Regression Model for Multiparty Electoral Data (with Joshua Tucker and Jason Wittenberg). Political Analysis 10, no. 1 (Winter 2002): 66–83.

Katz and King (1999) propose a statistical model for multiparty election data. They argue that ordinary least squares (OLS) regression is inappropriate when the dependent variable measures the share of the vote going to each party, and they recommend a superior technique. Regrettably, the Katz-King model requires a high level of statistical expertise and is computationally impractical for more than three political parties. We offer a sophisticated yet convenient alternative that involves seemingly unrelated regression (SUR). SUR is nearly as easy to use as OLS, yet performs as well as the Katz-King model in predicting the distribution of votes and the composition of parliament. Moreover, it scales easily to an arbitrarily large number of parties. The model has been incorporated into Clarify, a statistical suite that is available for free on the Internet.


Making the Most of Statistical Analysis: Improving Interpretation and Presentation (with Gary King and Jason WittenbergAmerican Journal of Political Science 44, no. 2 (April 2000): 347–61.

We demonstrate that social scientists rarely take full advantage of the information available in their statistical results. As a consequence, they miss opportunities to present quantities that are of greatest substantive interest for their research, and to express their degree of certainty about these quantities. In this paper, we offer an approach, built on the technique of statistical simulation, to extract the currently overlooked information from any statistical method, no matter how complicated, and to interpret and present it in a reader-friendly manner. Using this technique requires some sophistication, which we try to provide herein, but its application should make the results of quantitative articles more informative and transparent to all. To illustrate our recommendations, we replicate the results of several published works, showing in each case how the authors' own conclusions can be expressed more sharply and informatively, and how our approach reveals important new information about the research questions at hand. We also offer very easy-to-use software that implements our suggestions.


Electoral Surprise and the Midterm Loss in US Congressional Elections (with Kenneth Scheve). British Journal of Political Science 29 (July 1999): 507–21.

Alberto Alesina and Howard Rosenthal argue that surprise about the outcomes of US presidential elections accounts for two important features of the American political economy: the regular loss of votes experienced by the president's party in midterm congressional elections, and the systematic relationship between the party of the incoming president and macroeconomic performance. Scholars recently have begun conducting rigorous tests of the relationship between surprise and economic performance, but no similar empirical work exists on how surprise affects midterm elections. In this article, we offer the first direct test of the proposition that electoral surprise drives the midterm loss. Our analysis shows that the more surprised moderate voters are about the outcome of a presidential election, the lower is the probability that they will support the president's party in the subsequent midterm contest.


The Long-Run Advantages of Centralization for Collective Action (with Edward Schwartz). American Political Science Review 91 (September 1997): 685–93.

Institutional design can affect the logic of ongoing collective action in groups with heterogeneous members. This article corrects a mathematical error in a seminal article by Bendor and Mookherjee (1987) and shows how the amended result strengthens the case for centralized monitoring and enforcement mechanisms. In solving their original model, Bendor and Mookherjee neglected that groups under centralized control will become increasingly talented over time, as headquarters detects and replaces untalented members. Expected improvements in the talent of the group should heighten the incentive for its members to work and curtail the incidence of costly free-riding, as well as reduce the average per-worker cost of production. These gains in efficiency will not materialize in decentralized regimes, where the fraction of talented members will remain constant over time. Depending on the effectiveness of monitoring in the centralized group and the level of patience and talent in society as a whole, centralized regimes can produce greater group welfare than decentralized ones, even when decentralized institutions operate flawlessly.