Welcome to my website!

I am a Ph.D. candidate in Political Science at Columbia University specializing in formal theory and experimental methods.

My research uses game theory to study the internal organization of political parties. With incentivized experiments, I study how information affects voters’ behavior.

You can reach me at giovanna [dot] invernizzi [at] columbia [dot] edu.



“Public Information: Relevance or Salience?”. Games 2020, 11, 4. [paper]

How does salient public information affect voters’ behavior? In a majoritarian voting game with common preferences, rational voters could use public information as an information device (depending on accuracy) or as a coordination device (regardless of accuracy). A simple lab experiment contradicts both hypotheses: subjects tend to follow public information when it is salient, regardless of the information’s accuracy, but fail to use it as a source of coordination. In particular, it matters whether the information is recent: subjects are more likely to follow public information when it is provided closer to the voting decision. These findings are important because the salience of public information is easily manipulable by political actors.

working papers

“Electoral Competition and Factional Sabotage”. [paper]

Intra-party sabotage is widespread and can be detrimental to political parties. Despite its pervasiveness, little is known about the conditions facilitating sabotage — typically associated with factions’ opposing interests — and how parties react to contain it. I study a model of elections between two parties where factions can devote their resources to campaign for the party or to undermine each other. Each party redistributes electoral spoils among factions based on their internal rank — a noisy signal of their resource allocation. The model identifies conditions under which sabotage can be limited, and shows how parties’ internal organizations change to maximize the chances of winning the election. Results show that intra-party and inter-party competition are substitutes: as the electoral stakes increase, factions invest fewer resources into sabotage and devote more resources to promote the party. In equilibrium, parties adopt a winner-take-all incentive scheme when factions’ probability of ranking higher is increasing in campaigning effort, otherwise rewards are set to zero. When factions in the same party have different ideological preferences and parties choose policy platforms, in equilibrium the saboteur can be rewarded with policy concessions.

“Power Sharing, Mobilization and Party Organization”. With Carlo Prato. [paper]

We study the internal organization of political parties as the solution of a moral hazard problem between a party principal (or selectorate) and two factions. Factional mobilization effort bolster a party’s electoral chances but can only be imperfectly monitored—via an internal contest. We model a party’s internal organization as a system of “prizes”, an allocation of resources between winner and loser of the internal contest. We show that when (i) a party’s baseline electoral strength is low and (ii) electoral outcomes are not too responsive to mobilization efforts (e.g., when the electorate is polarized), there is an inverse relationship between inter-party power sharing and intra-party power sharing: when election winners keep most of the power, parties should allocate power across factions in a more egalitarian matter. Otherwise, party organization resembles a winner-take-all competition between factions. Our results help organize the empirically documented dispersion in party organizational structures (leadership autonomy, centralization of candidate selection, and the formal recognition of factions in the party statute).

“Political Norms”. With Michael Ting.

Recent political developments around the world have focused attention on the fraying of political norms, often understood as informal restraints on opportunistic behavior. This paper presents a theory of political norms that incorporates seemingly norm-breaking behavior as part of politicians’ equilibrium strategies. In the model, an election determines which party holds office in each period over an infinite horizon. Each period presents the party in office with an opportunity to modify a pre-existing status quo. Parties are constrained from modifying the status quo by both norms and other institutional actors. We show how much opportunism is needed to maintain at least partial cooperation under political conditions such as high polarization or electoral imbalance. The model also examines norm-breaking as a function of institutional factors such as party strength and the separation of powers.

“Conspiracy Theories and Political Accountability”. With Ahmed Ezzeldin Mohamed. Under Review. [paper] [pre-analysis plan]

Does the spread of conspiracy theories threaten democratic accountability? In this paper, we argue that conspiracy theories can hinder electoral accountability by helping bad politicians evade punishment, while reducing the political rewards of good performance in office. This happens via two mechanisms: (i) decreasing voters’ certainty about new information and the trustworthiness of the informational environment, and (ii) increasing indiscriminate mistrust of political institutions. To test this theory, we design a controlled online experiment among US subjects. Results show that conspiracy theories decrease certainty about new information, trust in sources of information, and trust in political institutions. This has negative implications for the role of voters in holding politicians accountable.

“Tra i Leoni: Revealing the Preferences Behind a Superstition”. First author, with J.B. Miller, T. Coen, M. Dufwenberg and L. Oliveira. Revise and Resubmit, Journal of Economic Psychology. [paper]

We investigate a superstition for which adherence is nearly universal. Using a combination of field interventions and a lab-style value elicitation, we investigate the strength of peoples’ underlying preferences, and to what extent their behavior is driven by social conformity rather than the superstition itself. Our findings indicate that both mechanisms influence behavior. While a substantial number of people are willing to incur a relatively high individual cost in order to adhere to the superstition, for many, adherence is contingent on the the behavior of others. Our findings suggest that it is the conforming nature of the majority that sustains the false beliefs of the minority.

work in progress

“Pre-Electoral Coalitions and Mergers in Multi-Party Electoral Competition”.

“Politics by Denunciation: Political Whistleblowing against Members of Parliament in Italy”. With Andrea Ceron.


The Logic of Collective Choice (2019) – Undergraduate level.
Undergraduate lecture course on collective choice.
Role: TA for Jeffrey Lax.

Political Science Math Camp (2019) – Ph.D. level.
A short math refresher providing a brief survey of some of the applied mathematics used in quantitative and formal methods in political science.
Role: Instructor.

Research Topics in Game Theory (2016, 2017) – Ph.D. level.
[2017 Evaluations] [2016 Evaluations]
The second course in the PhD formal theory sequence.
Role: TA for Carlo Prato.

Introduction to Comparative Politics (2018) – Undergraduate level.
An introduction to comparative politics for undergraduate students.
Role: TA for John Huber.

Game Theory and Political Theory (2017) – Ph.D. level.
The first course in the PhD formal theory sequence.
Role: TA for John Huber.



Columbia University, New York, NY.
Ph.D. Student in Political Science, 2015 – present.
Master in Political Science, 2016.

Bocconi University, Milan, Italy.
M.S. Summa Cum Laude, Economics and Social Sciences, March 2015.
B.A., Economics and Social Sciences, 2012.