We study the voting game with information uncertainty where agents can coordinate in groups. We show that strategic voting behaviors have a positive impact on leading to the "correct" decision, outperforming the common non-strategic behavior of informative voting and sincere voting. Our results give merit to strategic voting for making good decisions.

We reveal the surprising equivalence between a strategy profile being a strong equilibrium and leading to the decision favored by the majority (the informed majority decision): as the size of the vote goes to infinity, every ε-strong Bayes Nash Equilibrium with ε converging to 0 formed by strategic agents leads to the informed majority decision with probability converging to 1. On the other hand, we show that informative voting leads to the informed majority decision only under unbiased instances, and sincere voting leads to the informed majority decision only when it also forms an equilibrium. In our model, voters' preferences between two alternatives depend on a discrete state variable that is not directly observable. Each voter receives a private signal that is correlated with the state variable.

This is a joint work with Grant Schoenebeck, Biaoshuai Tao, and Lirong Xia.

Qishen Han is a Ph.D. student of Computer Science at Rensselaer Polytechnic Institute (RPI) since 2021, advised by Prof. Lirong Xia's.

His research interests mainly include the interdisciplinary area between theoretical computer science and economics, including computational social choice, information elicitation and aggregation, and algorithmic game theory. Qishen received a B.S. degree in Intelligence Science and Technology with a double major in Economics from Peking University in 2021.