Comparative Politics of Strategic Voting: A Hierarchy of Electoral Systems

What is the impact of electoral rules on the way people make decisions in the voting booth? Traditionally the literature about electoral systems argues that the size of the district magnitude determines the amount of strategic voting. I argue, however, that different electoral systems provide incentives that potentially undermine or facilitate the Duvergerian logic in practice. Contrary to the literature the results indicate that the impact of the district magnitude on the frequency of strategic voting in a given polity is conditional on the type of seat allocation system that defines how votes get translated into parliamentary seats.

Three Puzzles on Mathematics, Computation, and Games

In this lecture I will talk about three mathematical puzzles involving mathematics and computation that have preoccupied me over the years. The first puzzle is to understand the amazing success of the simplex algorithm for linear programming. The second puzzle is about errors made when votes are counted during elections. The third puzzle is: are quantum computers possible?Comment: ICM 2018 plenary lecture, Rio de Janeiro, 36 pages, 7 Figure

Dynamical Systems on Networks: A Tutorial

We give a tutorial for the study of dynamical systems on networks. We focus especially on "simple" situations that are tractable analytically, because they can be very insightful and provide useful springboards for the study of more complicated scenarios. We briefly motivate why examining dynamical systems on networks is interesting and important, and we then give several fascinating examples and discuss some theoretical results. We also briefly discuss dynamical systems on dynamical (i.e., time-dependent) networks, overview software implementations, and give an outlook on the field.Comment: 39 pages, 1 figure, submitted, more examples and discussion than original version, some reorganization and also more pointers to interesting direction

Revisiting Factors Associated with the Success of Ballot Initiatives with a Substantial Rail Transit Component, Research Report 10-13

This report presents the replication of an MTI study conducted in 2001 by Peter Haas and Richard Werbel. That research, itself a continuation of an earlier project completed in 2000, included an analysis of transportation tax elections in 11 urban areas across the nation and culminated in the identification of 17 community-level factors with potential impact on the success of ballot measures for sales tax increases to fund transportation packages with substantial rail components. Trends observed in these more recent case studies were generally highly consistent with the following findings from the 2001 study. Thus this analysis reaffirms the importance for community consensus amongst the business, elected and environmental communities, and accompanying depth of financial support. Once again, the difficulty of passing an initiative without well-funded, effective use of multimedia was validated, as was the importance of utilizing experienced campaign consultants. Some factors seemed less important in the current study than in 2001, including the effectiveness of presenting a multimodal package, the perception of benefits of a package being distributed throughout the voting district, the experience gained in recent transit elections, and the credibility of the transit agency. Finally, this compilation includes an exploration of “rebound” elections – those instances in which a failed measure is quickly followed by a successful one – and the factors that seem linked to achieving success in such instances

MMP-Elections: Equal Influence and Controlled Assembly Size

In an MMP election (Mixed Member Proportional) of a legislature, a QP-ballot supports party Q in a single-seat constituency and a list of candidates from P. With ꙍ(j) constituency seats won and list support in z(Pj) ballots, party Pj wins α(j) list seats, so that ꙍ(j)+α(j) becomes proportional to z(Pj). The pivotal party, Pj*, has the highest of all ratios ꙍ(j)/z(Pj). Proportionality implies, for all Pj passing some threshold, that [ꙍ(j)+α(j)]/z(Pj) ≥ ꙍ(j*)/z(Pj*). In the smallest proportional assembly, all ≥ are equalities and α(j*)=0. The pivotal party’s list support, z(Pj*), is naturally volatile. An election with α(j*)=0 tells that z(Pj*) list votes were wasted, and many voters learn it. Thus, between Bundestag elections 2017 and 2021, z(Pj*) dropped significantly. The smallest possible size of a proportional assembly rose from 709 to 794 seats, while the legal norm is 598. But an ad-hoc law of 2020 abandoned the proportionality rule, shrinking the assembly from 794 to 736 seats. ꙍ(j) measures and records the success of party Pj in the single-seat tallies; it also records how much α(j) is reduced by Pj’s constituency success. The paper compares this”traditional accounting” and“faithful accounting”: The latter records a QiPj-ballot, with Qi as constituency winner, with a tiny seat fraction that reduces α(j). Traditional accounting treats party Pj as a basic entity. Faithful accounting replaces it by the set Λ(Pj) of voters with list vote for Pj. This is a paradigm shift: Traditional accounting works even if constituency votes and list votes are collected in separate ballot boxes. But in faithful accounting, each ballot’s combination of Qi and Pj is essential. Main results: The change from traditional to faithful accounting brings the assembly size under control. A large inequality in voters influence is substantially reduced

Strategic voting under proportional representation and coalition governments : a simulation and laboratory experiment

The theory of strategic voting has been tested in experiments for elections in single member districts with three candidates or parties. It is unclear whether it can explain strategic voting behavior in a fairly common type of political system, multi-party systems with proportional representation, minimum vote thresholds, and coalition governments. In this paper, we develop a (non-formal) strategic voting game and show in a simulation that the model produces election scenarios and outcomes with desirable characteristics. We then test the decision-theoretic model in a laboratory experiment. Participants with a purely instrumental (financial) motivation voted in a series of 25 independent elections. The availability of polls and coalition signals by parties was manipulated. The results show that voters are frequently able to make optimal or strategic vote decisions, but that voters also rely on simple decision heuristics and are highly susceptible to coalition signals by parties

Comparative politics of strategic voting : a hierarchy of electoral systems

What is the impact of electoral rules on the way people make decisions in the voting booth? Traditionally the literature about electoral systems argues that the size of the district magnitude determines the amount of strategic voting. I argue, however, that different electoral systems provide incentives that potentially undermine or facilitate the Duvergerian logic in practice. Contrary to the literature the results indicate that the impact of the district magnitude on the frequency of strategic voting in a given polity is conditional on the type of seat allocation system that defines how votes get translated into parliamentary seats