Welcome to my website!

I am a PhD candidate at Columbia University specializing in formal political theory and experimental methods.  Starting Fall 2021 I will be a postdoctoral fellow at Collegio Carlo Alberto, Turin. 

My research uses game theory to study the 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.



“Tra i Leoni: Revealing the Preferences Behind a Superstition”. First author, with J.B. Miller, T. Coen, M. Dufwenberg and L. Oliveira. Journal of Economic Psychology 2021, 82. [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.

“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”. Under Review. [paper][slides]

Intra-party sabotage is a widespread phenomenon that undermines the strength of political parties. What brings opposing factions to engage in sabotage rather than enhancing the party image, and what strategies can parties adopt to contain it? This paper presents a model of elections in which intra-party factions can devote resources to campaign for the party or to undermine each other and obtain more power. The party redistributes electoral spoils among factions to motivate their investment in campaigning activities. The model shows that sabotage increases when the stakes of the election are low — e.g., in consensus democracies that grant power to the losing party — because the incentives to focus on the fight for internal power increase. It also suggests that the optimal party strategy for winning the election in the face of intra-party competition is to reward factions with high powered incentives when campaigning effort can be easily monitored, but treat factions equally otherwise.

“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. [paper]

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.

“Trust Nobody: How Voters React to Conspiracy Theories”. With Ahmed Ezzeldin Mohamed. Under Review. [paper] [pre-analysis plan]

How does exposure to conspiracy theories affect voters’ political attitudes and evaluations? Using an online experiment among US subjects, we show that exposure to conspiracy theories decreases voters’ trust in political institutions, such as mainstream parties and courts, as well as information providers. Subjects were exposed to conspiracy theories that are entirely unrelated to American domestic politics, which further underscores such narratives’ danger. However, results suggest that voters do not weigh unrelated conspiracies in their evaluation of politicians’ performance. Overall, our findings illustrate that an informational environment permeated by conspiracy theories could impede the functioning of democracy by eroding trust in its institutions, but that voters’ capacity to keep politicians accountable is resilient to unrelated information.

“Politics by Denunciation”. First author, with Andrea Ceron. [paper]

Judicial investigations of politicians are a fundamental component of politics, often leading to scandals. Yet, empirical evidence of the strategic determinants of judicial investigations is intrinsically hard to gather, a problem that has significantly limited the study of this important phenomenon. This paper studies the politicsbehind judicial investigations leveraging new data on prosecutors’ informants in 1125 episodes of misbehavior of Italian MPs involved in different crimes (1983-2019). Results provide evidence in favor of a political use of denunciations for corruption crimes: when a party weakens, the likelihood that political enemies denounce past misbehavior of members of the weakened party increases, suggesting that the political use of denunciation is elastic to changes in the electoral performance. The timing of past misbehavior is crucial: members of weakened parties are more likely to be accused of misbehavior that happened a long time before the accusation, which further supports the conjecture that accusations are politically motivated.

work in progress

“Does Electoral Volatility Beget Strong Alliances? A Theory of Multi-Party Competition”.

One fundamental issue of multi-party systems is the identification of future governments.
To address this mandate problem, parties typically form pre-electoral alliances. Despite being pervasive, little is known about the conditions facilitating different forms of pre-electoral alliances. This paper presents a model of electoral competition in which parties can form alliances before elections, and decide how binding these should be. Parties face a dynamic trade-off between insuring themselves against large shifts in public opinion and allowing flexibility to respond to future changes in voters’ preferences. Results show that more binding alliances such as mergers emerge in equilibrium when electoral volatility is high; otherwise, parties form more flexible pre-electoral coalitions. The model then analyses how this trade-off changes with alternative inter-party power sharing arrangements, voters’ uncertainty over parties’ platforms and party ideological polarization.

Other Writings

“Political Scandals”. [paper]

This literature review is the first attempt to gather the existing knowledge we have about political scandals. It is motivated by the widespread occurrences and the rising importance of scandals in shaping political events, and the corresponding (surprising) lack of attention by the academic community. While there is little empirical evidence of how scandals affect voters’ behavior, we lack a theoretical systematization of the phenomenon. This review therefore has two main contributions: first, it provides a broad overview of the political science literature that has been treating scandals. Secondly, it imparts a formal framework to think about scandals that might be useful in guiding future empirical and theoretical work.


Political Science Math Camp (2019, 2020) – Ph.D. level.
A review of basic calculus and linear algebra, as well as an introduction to fundamental notions of real analysis used in graduate courses in quantitative and formal methods.
Role: Instructor.

State Politics (2021) – Undergraduate level.
An introduction to american politics for undergraduate students.
Role: TA for Justin Phillips.

Voting and American Politics (2020) – Undergraduate level.
An introduction to american politics for undergraduate students.
Role: TA for Robert Erikson.

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

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

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.

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. in Political Science, 2021.
M.Phil. in Politial Science, 2017.
M.A. 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.