Matias Iaryczower - Associate Professor of Politics - Princeton University.   

My field of research is Political Economy. I use game theory and empirical methods to study how institutions and strategic considerations shape collective decision-making in courts, legislatures, and elections. One of the main lines of my theoretical research is the study of Power and Bargaining in Collective Bodies. I have studied the determinants of the power of leaders in organizations, the role of intermediaries in legislative bargaining, and whether competition between principals for influence over a group can be detrimental to its members. I am also interested -- and have written about -- electoral competition and political agency. My empirical work builds on the Structural Estimation approach. A key theme of my work in this area has been to understand how groups incorporate information about the relative merits of the alternatives under consideration into their decision-making process. My current empirical research focuses on the estimation of dynamic games in Congress and elections. [CV].

Selected Working Papers

We consider a dynamic model of an incumbent politician running for reelection to estimate the relative value of office to policy for US senators seeking reelection. We use the estimates of the model to quantify how career concerns and policy preferences affect electoral accountability and advertising in competitive and uncompetitive elections. 

We characterize the optimal contract in a principal-agent relationship when the principal can decide both the direction and implementation scale of a policy.

Selected Publications & Forthcoming

We consider a class of dynamic collective action problems in which a principal uses transfers to rally the support of a group of agents, in a context in which agents decisions are sequential and irreversible. We show that whenever the principals' provide value to the members of the group, introducing competition from a second principal reduces agents' welfare.

We estimate a model of voting with incomplete information in which committee members (judges in the US courts of appeals) can communicate before voting. We compare the probability of mistakes with deliberation with a counterfactual of no communication. We find that deliberation can be useful when judges tend to disagree ex ante and their private information is relatively imprecise; otherwise, it tends to reduce the effectiveness of the court.  

In a model of decentralized bargaining in legislatures, we show that some parties can endogenously emerge as brokers in equilibrium, transferring resources and voting rights between two parties that wouldn't negotiate directly with one another.

A model of judicial behavior that accounts for differences in ability and ideology among justices explains the decisions of the UK Lords of Appeal remarkably well, and improves the fit of the ideological model.

We estimate an empirical model of voting in Congress that accounts for uncertainty and private information about the quality of the proposal. We show that seniority and uncompetitive elections lead to higher ideological rigidity and curtail the role of information in policy-making.

We estimate a model of voting in Congress that allows for dispersed information about the quality of proposals. The results highlight the effects of bicameralism on policy outcomes. In equilibrium, the Senate imposes an endogenous supermajority rule of about four-fifths on members of the House. 

Proportional elections have more candidates, competing less aggressively in campaign spending, than those in majoritarian elections. 

Justices that are shielded from voters' influence on average (i) have better information, (ii) are more likely to change their preconceived opinions about a case, and (iii) make less mistakes than their elected counterparts.  

We estimate an equilibrium model of decision-making in the Court that takes into account both private information and ideological differences between justices. We find that in roughly one out of two cases, justices' prior beliefs and ideological biases are overpowered by case-specific information. 

Spending caps and compulsory voting can be pro-competitive in non-majoritarian electoral systems, leading to a larger number of parties contesting the election.

Party discipline is endogenously determined by backbenchers' beliefs about the extent of support to the leader within the party. We show that rewards that can be distributed publicly and on the spot (as opposed to promises of future benefits) are necessary for the leader to be powerful.

We provide conditions for judicial decisions to be sensitive to legislative lobbying, and find that lobbying falls the more divided the legislature is on the relevant issues. We apply this framework to analyze supreme court labor decisions in Argentina.

We examine the independence of Argentina's Supreme Court. Our results show an often defiant Court subject to constraints. The probability of voting against the government increases the less aligned a justice is with the President, but falls the stronger the control of the President over the legislature. 

Other Working Papers

We show that campaign Contributions have a large effect on the behavior of individual judges -- affecting the probability that they vote to overturn and the probability that they vote incorrectly -- but have a small effect on the decisions and effectiveness of the Court.

We consider strategic voting in sequential committees in a common value setting with incomplete information. 

Work in Progress   

  • "Collective Hold-Up", with Santiago Oliveros.
  • "Intertemporal Discrimination in Sequential Contracting", with Santiago Oliveros.
  • "Sequential Contributions to Multiple Joint Projects", with Santiago Oliveros.
  • "Dynamic Competition in Presidential Elections", with Gabriel Katz and Gabriel Lopez Moctezuma.
  • "The Causal Effect of Campaign Contributions on Legislators' Voting Behavior", with Gabriel Lopez Moctezuma. 

Current Students

  • Korhan Kocak (main advisor): Political Economy.
  • Brandon de la Cuesta (com. member): Comparative Politics / Quantitative Methods.
  • Romain Ferrali (com. member): Comparative Politics.
  • Ted Enamorado (com. member): Quantitative Methods / Comparative Politics.
  • Amanda Kennard (com. member): International Relations.
  • Sondre Solstad (com. member): Comparative Politics


  • Gabriel Lopez Moctezuma (main advisor): Political Economy / Quantitative Methods (Cowles Foundation PostDoc at Yale / AP at Caltech) 
  • Jidong Chen (com. member): Formal Theory / Comparative Politics (Postdoc, Wallis Institute of Political Economy, U. of Rochester).
  • Peter Buisseret (com. member): Formal Theory / Comparative Politics (Asst. Prof., Harris School of Public Policy, U. of Chicago).

Other Working Papers and Publications (In Spanish)

  • The Institutional Sources of Development in Argentina. Towards an Institutional Agenda. 2000. Editorial Universitaria de Buenos Aires  UNDP-CEDI. Project Directors: Mariano Tommasi and Pablo Spiller.