Download CV hi


Carlson, David & Ziegler, Jeffrey. ”The Role of Democratic Governance and Indirect Expropriation in International Investment Treaty Violations”. Accepted at Uluslararası İlişkiler - International Relations.

hi Download hi Supplementary Materials and Replication Data


Democracies are thought to violate treaties less frequently than non-democracies, yet democracies violate bilateral investment treaties (BITs) more often. Though democratic governments may intend to meet their international obligations, and though democratic institutions provide greater political constraints to encourage compliance, investment agreements may conflict with the goal of maintaining domestic public support. Specifically, we argue that credible elections create strong incentives for governments to side with domestic voters over foreign business interests, and to pass legislation that violates investment agreements. We use a data set of BIT violation complaints that better captures potential indirect expropriation to confirm prior findings that show a difference in violations by regime type. Importantly, however, governments are only more likely to violate BITs as credible elections approach. The results suggest that the ability of voters to sanction leaders is an important mechanism that incentivizes governments to potentially violate investment treaties through indirect expropriation.

Ziegler, Jeffrey. ”A Text-As-Data Approach for Using Open-Ended Responses as Manipulation Checks”. Forthcoming at Political Analysis.

hi Link hi Download hi Supplementary Materials and Replication Data


Participants that complete online surveys and experiments may be inattentive, which can hinder researchers’ ability to draw substantive or causal inferences. As such, many practitioners include multiple factual or instructional closed-ended manipulation checks to identify low-attention respondents. However, closed-ended manipulation checks are either correct or incorrect, which allows participants to more easily guess and it reduces the potential variation in attention between respondents. In response to these shortcomings, I develop an automatic and standardized methodology to measure attention that relies on the text that respondents provide in an open-ended manipulation check. There are multiple benefits to this approach. First, it provides a continuous measure of attention, which allows for greater variation between respondents. Second, it reduces the reliance on subjective, paid humans to analyze open-ended responses. Last, I outline how to diagnose the impact of inattentive workers on the overall results, including how to assess the average treatment effect of those respondents that likely received the treatment. I provide easy-to-use software in R to implement these suggestions for open-ended manipulation checks.

Gibson, James L., Miguel M. Pereira, & Jeffrey Ziegler. (2017). ”Updating Supreme Court Legitimacy: Testing the ’Rule, Learn, Update’ Model of Political Communication”. American Politics Research. 45(6), 980-1002.

hi Link hi Download hi Supplementary Materials


One of the more important innovations in the study of how citizens assess the U.S. Supreme Court is the ideological updating model, which assumes that citizens grant legitimacy to the institution according to the perceived distance between themselves and the Court on a unidimensional ideological (liberal–conservative) continuum. Under this model, citizens are also said to update this calculation with every new salient Supreme Court decision. The model’s requirements, however, do not seem to square with the long-established view that Americans are largely innocent of ideology. Here, we conduct an audit of the model’s mechanisms using a series of empirical tests applied to a nationally representative sample. Our general conclusion is that the ideological updating model, especially when supplemented with the requirement that citizens must become aware of Court decisions, simply does not square with the realities of American politics. Students of Supreme Court legitimacy may therefore want to search for other theories of legitimacy updating.


  title={Updating Supreme Court Legitimacy: Testing the “Rule, Learn, Update” Model of Political Communication},
  author={Gibson, James L. and Pereira, Miguel M. and Ziegler, Jeffrey},
  journal={American Politics Research},



hi GitHub Page for Source Code


Accompanying R package for "A Text-As-Data Approach for Using Open-Ended Responses as Manipulation Checks" to help researchers analyze manipulation checks that employ open-ended responses.

Working Papers

Ziegler, Jeffrey. ”Responsiveness and Unelected Leaders: Lessons from the Catholic Church”.

hi Download


Are leaders responsive to their followers’ political preferences over time even when formal accountability mechanisms, such as elections, are weak or absent? I argue that unelected leaders have incentives to be responsive because they rely on dedicated members for legitimacy and support. I test this theory by examining the Catholic Church and its unelected leader, the pope. First, I analyze over 10,000 papal statements to confirm that the papacy is responsive to Catholics’ concerns. Second, I conduct survey experiments using nationally representative samples of Catholics in Brazil and Mexico to investigate how Catholics react to responsiveness. Catholics increase their organizational trust and participation when they receive papal messages that reflect their concerns, conditional on their existing commitment to the Church and their agreement with the Church on political issues. The evidence suggests that even in organizations without elections, leaders reaffirm members’ political interests because followers support organizations that are responsive.

Cheruvu, Sivaram & Jeffrey Ziegler. ”How Much Influence Do Opinion Writers Have on Per Curiam Courts? Uncovering Author Drift in Written Decisions Using Neural Networks”.


Research that assesses judges' political preferences typically focuses on courts that publish individual votes and opinions, yet many courts issue per curiam judgments that do not permit public dissent. To overcome this limitation, we use convolutional neural networks (CNNs) to model the variation in judges' expressed preferences from the language in aggregated judgments. Specifically, we apply CNNs to analyze the written opinions of judge-rapporteurs and advocates-generals from the Court of Justice of the European Union. We estimate along a pro-anti EU dimension how judgments differ within (1) each case to the advocates-general's opinion, providing a baseline for the case's legal merits, and (2) each judge-rapporteur, which measures how judges alter their writing across cases. Our results provide novel empirical support for theoretic models of European judicial decision-making: more pro-EU opinions driven by the Court, not the advocates-general or judge-rapporteur, are associated with larger chambers and stronger external signals of compliance.

Miller, David R. & Jeffrey Ziegler. ”Preferential Abstention in Conjoint Experiments”.


Social scientists increasingly use conjoint experiments to mimic political decisions that ordinary people face, such as selecting news stories or voting for public officials. Conjoint designs, however, do not always mirror the real-world decisions that individuals make because respondents are forced to select only one of two options and cannot abstain. First, we show through simulations that allowing respondents to abstain can yield different average marginal component effects (AMCEs) depending on the (1) reference category of comparison and (2) variation in respondents’ "cost" to select one of the alternatives. Second, we demonstrate empirically how omitting a realistic abstention option leads to over- and under-estimation of the AMCEs by replicating two conjoint experiments. We provide an online application to help practitioners explore how forcing respondents to express a preference when none exists may impact the results of their conjoint experiment.

Grants and Awards

  • Graduate Research Seed Grant, Washington University in St. Louis, Department of Political Science (2018)

  • Dissertation Support, Danforth Center on Religion and Politics (2018)

  • Lois Roth Endowment, Fulbright Project Support (2014)

  • Fulbright Research Grant, Umeå University (2013-2014; Adviser: Torbjörn Bergman)

  • Gudrun Gytel Fund Scholarship (2011)

  • Larsen Family Scholarship (2011)

  • ScanDesign Scholarship (2011)