Enriqueta Aragones' Research


The following is a description of my research interests.
Most of my research is in Political Economics, but I have also done some work on Social Choice, and Learning.

Political Economics

Political Economics is a term coined by Roger Myerson to define the application of Economic Analysis to political institutions. It is devoted to the study of political institutions by the methods for analysis of behavior developed in Economics.

Social and political institutions are enduring systems of social constraint on human behavior. Institutional reforms are generally advocated with the goal of improving the people's welfare in a society. Economic analysis has been developed to provide a methodology to evaluate proposals to reform institutions.

Institutions are represented as simplified games where the preferences of all actors (parties, candidates, voters, …) are precisely specified. We analyze the strategic behavior of the actors in any given situation represented by a game, and look for its equilibria, that is, profiles of best responses that lead to stable outcomes. Equilibria allows us to make predictions over the consequences of a given political institution over society's welfare. A proposed reform of a political institution would then correspond to a change in the rules of this political game, which could in turn change the rational equilibrium behavior in the game.  

By examining many such models, and by relating the theoretical analysis to empirical findings from comparative politics, we can gradually build a better understanding of the significance of different political institutions. Work in this area may ultimately have great practical value in finding institutional structures that can improve the chances for the sustenance and spread of representative democracy in the world.

There is not yet much consensus about the basic organizing paradigms and principals of political economics. Understanding that the choice among different forms of democracy is a matter of great potential importance, we should learn more about how democratic structures may affect the conduct of politicians and the performance of the government

Most of my research in Political Economics is devoted to the study of the strategic interactions among the agents (candidates, parties, voters, …) involved in an election. The set of topics I have studied is the following:
1)    Negativity Effect: focuses on the voters’ processing information task when facing an election.
2)    Political Ambiguity: analyzes the strategic behavior of political candidates when deciding on the amount of information to deliver to voters.
3)    Campaign Rhetoric: devoted to analyze the role of rhetoric in electoral campaigns using a game theoretical framework.
4)    Elections with a  Favored Candidate: based on the classical spatial model assumes an exogenous asymmetry between the candidates.
5)    Participatory Democracy: analyzes different democratic systems and compares them.
6)    Participation: discusses several reasons to explain the elections turnout.
7)    Government Formation: studies the possibilities of governing coalitions in a multidimensional spatial model.
8)    Electoral Issues: investigates the selection of issues to be debated during the electoral campaigns.

1) Negativity Effect
: This project deals with the limitations to acquisition and processing of information faced by the different agents involved in an election.  The aim of this research is to find a convincing way to model the behavior of these different agents.  Analyzing the information available to each type of agent, and the use they make of it, is a most important step in this direction.  In particular, I am interested in the interplay between rational strategic behavior and psychological biases.

Negativity Effect and the Emergence of Ideologies in Journal of Theoretical Politics (1997) 9 (2):198-210. In this paper I study the information processing tasks of the voters.  It presents a model that attempts to explain certain empirical characteristics of the behavior of voters facing an election.  The main result of this model is that parties whose only objective is to maximize the number of votes behave as if they had an ideology, that is, an ideal point in the policy space.

A Dynamic Model of Multiparty Competition In this paper we offer a generalization of the previous model for the case of three-party competition.  The results we find for three party competition are qualitatively the same, and I show that they can be easily generalized to more than three parties.  This paper allows us to test the robustness of the previous results.  Furthermore, if we assume that parties and candidates have different objectives, an additional result of the three-party model shows the formation of parties, as infinitely lived agents with a certain ideology, out of the competition of myopic candidates freely choosing policy positions. 

2) Ambiguity: Focusing on the ambiguity of candidates during electoral campaigns, we try to explain how in a political model with fully rational voters, political ambiguity can increase the number of voters to whom a party may appeal.

Strategic Ambiguity in Electoral Competition, co-authored with Zvika Neeman. Published in Journal of Theoretical Politics (2000) 12(2):183-204. This paper is about the strategic choice of platforms by candidates. In particular, it focuses on the amount of information that candidates are willing to release to the voters, analysing a spatial model of two party electoral competition.  We characterize those cases in which parties prefer to present ambiguous platforms and differentiate from each other ideologically, and those cases in which parties prefer to present identical ideologies with specific platforms.

Ambiguity in Election Games, joint with Andrew Postlewaite. Published in Review of Economic Design (2002) 7 (3): 233-255. We construct a model in which the ambiguity of candidates allows them to increase the number of voters to whom they appeal. We focus our analysis on two points that are central to obtain ambiguity in equilibrium: restrictions on the beliefs that candidates can induce in voters, and intensity of voters' preferences. The first is necessary for a pure strategy equilibrium to exist, while the second is necessary in order to obtain ambiguity in equilibrium when there exists a Condorcet winner in the set of pure alternatives and when the candidates' only objective is to win the election. The intuition is that an ambiguous candidate may offer voters with different preferences the hope that their most preferred alternative will be implemented. We also show that if there are sufficiently many candidates, ambiguity will not be possible in equilibrium, but a larger set of possible policies increases the chance that at least one candidate will choose to be ambiguous in equilibrium.


3) Campaign Rhetoric: Campaign statements are cheap talk, that is, fixing all actions of all participants, no payoffs differ when messages alone are changed. We outline necessary ingredients of a rational actor model in which campaign rhetoric can matter. We analyze how rhetoric can matter in repeated election models. We show how candidates may (rationally) choose to maintain a reputation for fulfilling campaign promises. We further discuss the determinants of the set of promises that candidates can credibly make in equilibrium.

Political Reputations and Campaign Promises, joint with Thomas Palfrey and Andrew Postlewaite. Published in the Journal of the European Economic Association, (2007) 5 (4): 846-884. We analyze conditions under which campaign rhetoric may affect the beliefs of the voters over what policy will be implemented by the winning candidate of an election. We develop a model of infinitely repeated elections with complete information in which candidates are purely ideological. We analyze an equilibrium in which all campaign promises are believed by voters, and honored by candidates, and voters' strategies involve a credible threat to punish candidates who renege of their campaign promises. We obtain that the degree to which promises are credible in equilibrium is an increasing function of the value of a candidate's reputation.

Information transmission and Reputational Dynamics in Repeated Elections joint with Thomas Palfrey and Andrew Postlewaite. We explore an equilibrium model of information transmission in repeated elections with two parties. The parties use strategies that trade off the long term benefits of maintaining a reputation for trustworthiness with the short term policy benefits of holding office. Several different equilibrium regimes may arise endogenously, including "alternating reputations" where one party enjoys a good reputation for several periods, and then loses it, and then reagins it at a later point in time. This should lead to a stochastic cycle of reputations in which parties transmit useful information to the voters.

Campaign Rhetoric: a learning model, joint with Thomas Palfrey and Andrew Postlewaite. We analyze conditions under which a candidate's campaign rhetoric may affect the beliefs of the voters over what policy the candidate will implement in case he wins the election. We develop a model of repeated elections with asymmetric information in which candidates are purely ideological and voters do not know the policy preferences of the candidates. In this model voters acquire information regarding the candidates' policy preferences from the fact that candidates renege or fulfill their campaign promises.

Campaign Rhetoric and Endorsements in Electoral Competition, joint with Andrew Postlewaite. We analyze the strategic interaction of political parties and potential endorsers during an electoral campaign in order to affect the outcome of the election. As a result of this interaction, voters' beliefs on the preferences of the parties may be affected.  Political campaigns can be represented by signalling games, and the application of the cheap talk refinement literature to them appears to be a helpful tool to understand the beliefs that can be induced in voters.

4) Elections with a Favored Candidate: We examine competition in the standard one-dimensional Downsian model of two-candidate elections, where one candidate (A) enjoys an advantage over the other candidate (D).  Voter preferences are Euclidean, but any voter will vote for candidate A over candidate D unless D is closer to her ideal point by some fixed distance. The location of the median voter's ideal point is uncertain, and its distribution is commonly known by both candidates. The candidates simultaneously choose locations to maximize the probability of victory.  Pure strategy equilibria often fail to exist in this model, except under special conditions about the magnitude of the advantage and the distribution of the median ideal point.

Mixed Strategy Equilibrium in a Downsian Model with a Favored Candidate in Journal of Economic Theory (2002) 103 (1): 131-161. This is a joint project with Thomas Palfrey. We consider a finite policy space within the unit interval and solve for the essentially unique symmetric mixed equilibrium. We show that candidate A adopts more moderate policies than candidate D, and we obtain some comparative statics results about the probability of victory and the expected distance between the policies proposed by the two candidates.

The Effect of Candidate Quality on Electoral Equilibrium: An Experimental Study in American Political Science Review (2004) 98 (1): 77-90. This is a joint project with Thomas Palfrey. We test three of the predictions from the previous paper, namely: 1) the better candidate adopts more centrist policies than the worse candidate, 2) the equilibrium is statistical, in the sense that it predicts a probability distribution of outcomes rather than a single degenerate outcome, and 3) the equilibrium varies systematically with the level of uncertainty about the location of the median voter. We use laboratory experiments and find strong support for all three. We also observe some biases and show that they can be explained by Quantal Response Equilibrium.

Spatial Competition Between Two Candidates of Different Quality: The Effects of Candidate Ideology and Private Information in Social Choice and Strategic Decisions: Essays in Honor of Jeffrey S. Banks, Ed. David Austen-Smith and John Duggan, (2005) Berlin: Springer. This is a joint project with Thomas Palfrey. We extend the previous model by assuming that candidates care not only about winning but also have policy preferences. We also assume that there is two-dimensional private information: candidates’ ideal points as well as their tradeoffs between policy preferences and winning. We characterize the effects of increased uncertainty about the median voter, the effect of candidates’ policy preferences, and the effects of changes in the distribution of private information on the equilibrium outcome.

Candidate Quality in a Downsian Model with a Continuous Policy Space, in Games and Economic Behavior (2012) 75:464-480. This is a joint paper with Dimitrios Xefteris. This paper characterizes a unique mixed strategy Nash equilibrium in a one-dimensional Downsian model of two-candidate elections with a continuous policy space, where candidates are office motivated and one candidate enjoys a non-policy advantage over the other candidate. We show that if voters’ utility functions are concave and the median voter ideal point is drawn from a unimodal distribution, there is a mixed strategy Nash equilibrium where the advantaged candidate chooses the ideal point of the expected median voter with probability one and the disadvantaged candidate uses a mixed strategy that is symmetric around it. Existence conditions require the variance of the distribution to be small enough relative to the size of the advantage.

Imperfectly informed voters and strategic extremism, forthcoming in International Economic Review, is a joint paper with Dimitrios Xefteris. We analyze an electoral competition model with two office motivated candidates where voters use shortcuts (e.g. interest-group/media endorsements) to infer the policy platforms of the competing candidates. That is, voters have imperfect information about the candidates' policy proposals: they do not observe the exact policy proposals of the candidates but only which candidate offers the most leftist/rightist platform. We also consider the possibility that voters use a biassed tie breaking rule that assigns a non-policy advantage to one of the candidates. In the unique equilibrium of the game the behavior of the two candidates tends to maximum extremism, but it may converge or diverge depending on the size of the candidate's advantage. For small values of the advantage candidates converge to the extreme policy that is most preferred by the median voter and for large values of the advantage candidates' strategies diverge: each candidate specializes in a different extreme policy. Our analysis shows that the imperfect information of the voters about the candidates' strategies leads candidates to choose extreme policies, while the presence of the non-policy advantage leads candidates to choose diverging policies.

Voters' private valuation of candidates' quality, is a joint paper with Dimitrios Xefteris. Different voters might have different valuations of candidates' qualitative features. We argue that this intuitive fact acts as a strong stabilizing force on electoral competition dynamics (pure strategy equilibria may exist, unlike when all voters favor the same candidate); and, perhaps more importantly it affects candidates' platform moderation incentives in a rather asymmetric manner. If voters are evenly split, in terms of their candidates' quality valuations, then both candidates have incentives to locate sufficiently near -but not necessarily exactly at- the expected median voter's ideal policy. However, as the number of voters who favor the same candidate rises, firstly, only the advantaged candidate faces increasing incentives to further moderate, but then -after this number surpasses a certain threshold- only the disadvantaged candidate is increasingly incentivized to choose extreme policies. As a result, maximum equilibrium differentiation follows a non-trivial U-shaped pattern: it is minimal when a sufficiently small majority of voters favors a certain candidate.


5) Participatory Democracy:
This is a joint project with Santiago Sanchez-Pages. Participatory Democracy is a collective decision making process that combines elements from both Direct and Representative Democracy. Citizens have the power to decide on policy and politicians assume the role of policy implementation.

A theory of Participatory Democracy based on the real case of Porto Alegre in the European Economic Review (2009) 53: 56-72. We explore a formal model of Participatory Democracy inspired in the experience of Participatory Budgeting implemented in the Brazilian city of Porto Alegre. Our model builds on the research on meetings with costly participation by Osborne, Rosenthal, and Turner (2000). The aim of this paper is to understand how Participatory Democracy operates, and to study its characteristics and implications over the behavior of citizens and politicians and over the final policy outcomes.

Accountability and incumbency (dis)advantage. This paper analyses the problem that an incumbent faces during the legislature when deciding how to react to citizen mandates such as the outcome of referenda or popular initiatives. We argue that these mandates constitute a potential source of incumbency (dis)advantage when citizens factor into their evaluation of the incumbent his reaction to these proposals. We characterize conditions under which incumbents use these policy decisions in their advantage. This is more likely to be the case the higher the importance citizens award to their mandate, the smaller the disalignment between the incumbent and the citizens on the issue their mandate refers to, and the more office motivated the incumbent is. Otherwise, the incumbent chooses to ignore the citizens' proposal at the risk of losing reelection. Finally, we apply our findings to the experience with participatory democracy in Brazil and to the responsiveness of politicians to popular initiatives in US states.


6) Participation:
This is a joint project with Itzhak Gilboa and Andrew Weiss.

Making Statements and Approval Voting in Theory and Decision (2001) 71(4):461-472. We assume that people have a need to make statements, and construct a model in which this need is the sole determinant of voting behavior. In this model, an individual selects a ballot that makes as close a statement as possible to her ideal point, where abstaining from voting is a possible (null) statement. We show that in such a model, a political system that adopts approval voting may be expected to enjoy a significantly higher rate of participation in elections than a comparable system with plurality rule.

7) Government Formation:

Government Formation in a Two Dimensional Policy Space in the International Journal of Game Theory, (2007) 35 (2): 151-184. Given any allocation of parliament seats among parties, we characterize all the stable government configurations (supported by at least a majority of the parliament) in terms of winning coalitions and policy outcomes. We consider a two dimensional policy space and we assume that there are four parties that care mainly about holding office, and only instrumentally about policy. We find that for any distribution of seats in the parliament only two scenarios are possible: either there is a party that is a member of almost all equilibrium coalitions (dominant party scenario) or there is a party that is never a member of an equilibrium coalition (dominated party scenario). We characterize the key party for each possible scenario and we show that it is sufficient that the key party has intense preferences over one the issues to guarantee the formation of a stable government coalition.

The Key Party in the Catalan Government in the Spanish Economic Review (2007) 9 (4): 249-271. This paper analyzes the different compositions of the catalan governing coalitions during the current democratic period, and offers some predictions about the coalitions that can be expected in the future. During this period, in catalan politics, there have been two main political issues over which the different parties have taken positions: rightist versus leftist with respect to economic policy, and sovereign versus centralist with respect to the power distribution within the state. I find that for any allocation of parliament seats there is a key party: a party that has a clear advantage in terms of being able to decide the composition of the governing coalition. I show the features that allow a party to become the key party and those that affect the size of the advantage of the key party.

An Automated Model of Government Formation is a joint project with Pilar Dellunde published in The Political Economy of Democracy, edited by E. Aragončs, C. Beviá, H. Llavador, N. Schofield, published by Fundación BBVA (2009). We propose a formal model of bargaining for government formation in a parliamentary democracy that permits the analysis of the effects of a large class of bargaining strategies on the possibility of reaching agreements and on the policy compromise of the members of the government coalition that forms. We also propose a complementary algorithm that, applied to the proposed model, would allow to implement the simulations of the interplay of different sets of strategies. The implementation of the combination described above should shed some light on the performance of the different strategies according to the benefit they produce for the parties.

Towards a new Catalan party system, in The International Catalan View, winter 2015. In the last few years the political preferences of the Catalan society have experienced intense and continuous changes. Large popular demonstrations and the results of many different polls are the evidence of such changes. Increasing spread over the population of the desire for an independent state has become the main issue of political debates. Political parties have been forced to adapt their positions on the political arena to the new preferences of the society. The party system, that had been a stable system for over two decades, is bound to give rise to a new party constelation.


Negotiations and political strategies in the contest for Catalan independence is a joint project with Clara Ponsatí published in Catalonia: A New Independent State in Europe?, edited by Xavier Cuadras-Morató, published by Routledge (2016). This chapter analyses negotiations between the Catalan and the Spanish governments and their interaction with electoral political competition in the present contest for Catalan independence. Frustration to attain an agreement has fuelled powerful grass roots pro-independence movements, and has led to the parallel evolution of voters' political preferences, shifting them towards a more intense and generalised desire for an independent state. We discuss the realignment of political parties’ platforms this has brought in response. Polarised agendas over Catalan independence have precipitated in the present situation of open conflict between the Catalan and the Spanish governments.


Government Coalition Bargaining is a joint project with Pilar Dellunde and Xavier Vilŕ. It aims at constructing the algorithm proposed in "An Automated Model of Government Formation". We simulate the interplay of several parties using different strategies, and evaluate the payoffs they obtain from the outcomes of the simulation. We compare the performance of the different strategies in different setups, and conclude about the optimality of each one of the strategies characteristics. We also allow strategies to evolve over the paying time in order to find the optimal strategy for a party when facing a given environment. Finally, we find the overall optimal strategies of parties that use strategies that improve over time.


8) Electoral competition over different issues:


Electoral Competition through Issue Selection, in the American Journal of Political Science (2015) 59(1):71-90, is a joint project with Micael Castanheira and Marco Giani. In reality, parties can manipulate voters’ priorities by emphasizing issues selectively during the political campaign. This phenomenon, known as priming, may allow parties to cut down their investment in solving the issues that they intend to mute. We develop a model of endogenous issue ownership in which two vote-seeking parties (i) invest to attract voters with better policy proposals and (ii) choose a communication campaign to focus voters’ attention on specific issues. We identify novel feedbacks between communication and investment. In particular, we find that stronger priming effects can backfire and constrain parties to invest more resources in all issues, including the ones they would otherwise prefer to mute. We also identify under which conditions parties prefer to focus on their ‘historical issues’ or to engage in issue stealing. Typically, the later happens when priming effects are strong and parties are less differentiated.


Preference shock and party consistency. I develop a two party electoral competition model in order to analyze the effects of an exogenous preference shock on the strategic policy choice of parties. I find that on the one hand, if the preference shock affects the issue that is currently most salient, then both parties strategically shift their policy choices in the direction of the shock, however the shifts are asymmetric: the policy shift of the party that is most favored by the preference shock is smaller. On the other hand, if the preference shock affects an issue that was not the most salient before and becomes salient because of the shock itself, then both parties strategically shift their policy choices towards the ideal point of the median voter of that issue. And again, the parties policy shift is asymmetric: the reaction of the party that is most favored by the preference shock is smaller.  Finally, I show that the effects of a large policy shift that some parties perform when they are optimally reacting  to a voters' preference shocks may break the party's internal equilibrium among its different factions, implying that exogenous preference shocks may cause important changes in a party system.


Social Choice

A derivation of the money rawlsian solution in  Social Choice and Welfare (1995) 12: 267-276. I study the set of envy-free allocations for economies with indivisible objects and quasi-linear utility functions.  In this paper, I find the minimal amount of money necessary for its non emptiness when negative distributions of money are not allowed.  I also find that, when this is precisely the available amount of money, there is a unique way to combine objects and money such that these bundles may form an envy-free allocation. Based on this property, I describe a solution to the envy-free selection problem following a pseudo-egalitarian criterion.


Fact Free learning  in the American Economic Review (2005) 95 (5):1355-1368. This is a joint paper with Itzhak Gilboa, Andrew Postlewaite, and David Schmeidler. We offer an explanation of how people may learn without getting new factual information. We show that given a database, finding a small set of variables that obtain a certain value of accuracy is computationally hard, in the sense that this term is used in computer science and we discuss some of the implications of this result and of fact-free learning in general.

Rhetoric and analogies in Research in Economics (2014) 68:1-10. This is a joint paper with Itzhak Gilboa, Andrew Postlewaite, and David Schmeidler. The art of rhetoric may be defines as changing other people's minds (opinions, beliefs) without providing them new information. One technique heavily used by rhetoric empploys analogies. Using analogies one may draw the listener's attention to similarities between cases and to re-organize existing information in a way that highlights certain regularities. In this paper we offer two models of analogies, discuss their theoretical equivalence and show that finding good analogies is a computationally hard problem.