Representation-Compatible Power Indices

This paper studies power indices based on average representations of a weighted game. If restricted to account for the lack of power of dummy voters, average representations become coherent measures of voting power, with power distributions being proportional to the distribution of weights in the average representation. This makes these indices representation-compatible, a property not fulfilled by classical power indices. Average representations can be tailored to reveal the equivalence classes of voters defined by the Isbell desirability relation, which leads to a pair of new power indices that ascribes equal power to all members of an equivalence class.Comment: 28 pages, 1 figure, and 11 table

All Is Changed, Changed Utterly? The Causes and Consequences of New Zealand's Adoption of MMP

New Zealand's political landscape experienced a seismic shift in 1993, when the country replaced the First-Past-The-Post (FPTP) voting system it had inherited from its British colonial past with a new Mixed Member Proportional (MMP) voting system. This article traces how this change to New Zealand's voting system has impacted on three particular themes running through New Zealand's wider electoral laws and practices: representation of the voters' will, the constitutional balance of power, and engaging the voting population in the electoral process

Fair votes in practice

Criteria for a good voting system have been given particularly careful scrutiny in recent years, with general agreement that the core values are fair results, voter power and choice, and local representation. This paper reexamines the basic ideas of three widely used voting systems, the Single Transferable Vote, List-PR, and Mixed Member Proportional (MMP); and evaluates their performance in terms of both principles and practice. It looks particularly closely at proportionality, examining three aspects:n linearity, the threshold for representation and the threshold for gaining a majority. As regards local representation, an important question is how to design multi-member constituencies. It will be argued that using constituencies based on natural demographic boundaries (such as local government areas) can combine better local representation with stability over time and better proportionality. STV is unsurprisingly best for voter empowerment and choice, as those are parts of its basic idea. Broad conclusions are summarised within the Summary on page 1 of the paper. The paper makes use of recent public availability of large preferential voting data sets for STV elections, making possible new analyses of how STV functions in practice, and of voter behaviour, particularly examining how voters' second preferences relate to their first preferences.Comment: 31 pages, 12 figures, submitted to J Roy Statist Soc A as a potential Discussion Pape

Essays in political economy

This thesis is comprised of three chapters. In the first chapter, I examine a voting model where two political parties have fixed positions on a unidimensional policy space but where the implemented policy is the convex combination of the two positions and study the effects of opinion polls on election results and social welfare. Voters are completely agnostic about the distribution of preferences and gain sequential and partial information through series of opinion polls. Voters' behavior is driven in part by regret minimization. The mass of undecided voters decreases monotonically with the number of polls, but may not necessarily disappear. Voters who remain undecided have centrist ideologies. Finally, social welfare is not necessarily increasing in the number of polls: having more polls is not always better. Features of the model are con firmed by empirical evidence. In the second chapter, which is a joint work with Agustin Casas and Guillermo Diaz, we evaluate the effect of an institutional provision designed to increase accountability of local officials, and we show that its implementation can lead to a distribution of power within the legislature which is not consistent with voters' true preferences. The cause of this inconsistency is the ballot design which asymmetrically affects the officials listed on it. We analyze the case of the Lima's 2013 city legislature recall referendum and show that the design of the referendum ballot had adverse and signifficant effects on the composition of the Lima's city legislature. We also show that the election results with more \neutral" ballot designs would have been signifficantly different, and the composition of the legislature would have been more representative of voters' true preferences. More specifically, we use our results to simulate the outcome of the election with a random order of candidates. Even though the voters' fatigue is still present, it affects all parties equally, obtaining a more faithful representation of the voters' preferences. Finally, the third chapter is a joint work with Marco Serena. For small electorates, the probability of casting the pivotal vote drives one's willingness to vote, however the existence of costs of voting incentivizes ones abstention. In two-alternative pivotal-voter models, this trade-off has been extensively studied under private information on the cost of voting. We complement the literature by providing an analysis under complete information, extending the analysis of Palfrey and Rosenthal [1983. A strategic calculus of voting. Public Choice. 41, 7-53]. If the cost of voting is sufficiently high at least for supporters of one of the two alternatives, the equilibrium is unique, and fully characterized. If instead the cost of voting is sufficiently low for everyone, we characterize three classes of equilibria and we find that all equilibria must belong to one of these three classes, regardless of the number of individuals. Furthermore we focus on equilibria which are continuous in the cost of voting. We show that this equilibrium refinement pins down a unique equilibrium. We conclude by discussing an application of our findings to redistribution of wealth.Polling in a Proportional Representation System / Christos Mavridis. -- The last shall be the first: failed accountability due to voters fatigue and ballot design / Christos Mavridis, Agustin Casas and Guillermo Diaz. -- Costly voting under complete information / Christos Mavridis, Marco SerenaPrograma Oficial de Doctorado en EconomíaPresidente: Pablo Amorós González; Secretario: Fracisco Marhuenda Hurtado; Vocal: Orestis Troumpouni

A Vote Cast; A Vote Counted: Quantifying Voting Rights through Proportional Representation in Congressional Elections

The current winner-take-all or first-past-the-post system of voting promotes an inefficient market where votes are often wasted. In this system, representatives are selected from a single district in which the candidate with the plurality of votes gains victory. Candidates who appear non-generic can rarely, if ever, expect to receive the most votes in this system. This phenomenon is especially apparent when African-Americans and other minority groups seek elected office. In part because white voters constitute at least a plurality of voters in every state except Hawaii, minorities in the forty-nine other states have had historically little success in gaining election to the United States Senate. As a consequence, the only real opportunity for minorities to gain access to federal elected office remains limited to the United States House of Representatives. The flaws of the winner-take-all-system and single member district are readily apparent. First, significant blocs of voters are consistently denied the right to elect a truly preferred candidate, because such candidates can almost never expect to receive the most votes. Consequently, many potential candidates are deterred from running because the prospect for victory is so slim. As a result, large numbers of voters are often forced to select the candidate they believe has the greatest chance of winning, rather than their preferred candidate. In addition, many voters in a winner-take-all system are represented by persons they did not support. For instance, in 1994, while Democratic candidates for Iowa\u27s five seats in the United States House of Representatives received 42% of the total votes cast in Iowa, none of Iowa\u27s five congressional seats was won by a Democrat. Similarly, in 1992, Republican congressional candidates garnered 48% of the two-party statewide vote in North Carolina, but won only four of twelve seats. Thus, many losing votes may be considered wasted. Wasted votes may also include those cast for the victorious candidate: any vote cast in addition to the number needed for victory might as well have never been cast. Thus, in landslide races, where the prospect of wasting one\u27s vote is high, the incentive to vote seems almost non-existent. Since over 75 percent of congressional races in any given election tend to be landslide races, many eligible voters do not vote. This Article considers an alternative system of voting: proportional representation, of which there are two basic forms, List System and Choice Voting/Single Transferable Vote. In the list system, a voter simply selects one party and its slate of candidates. Thereafter, the seats are allocated on the basis of the share of votes each party earned. For instance, in the Iowa congressional example discussed above, instead of receiving zero congressional seats with 42% of the statewide vote, the state Democratic Party would have earned two seats out of the available five. Often, with the list system, a minimum share of votes (such as 5%) is required for a party to earn representation. Alternatively, in a choice voting system, a voter simply ranks candidates in order of preference (first choice, second choice, etc.). Once a voter\u27s first choice is elected or eliminated, the voter\u27s excess votes are transferred to subsequent preferred candidates until all the seats are filled. In either arrangement, proportional representation would diminish wasted votes, provide greater opportunities for minority groups to gain access to legislative positions, and offer greater incentive for eligible voters to vote. Though proportional representation risks the election of fringe groups (such as hate groups), a minimum bar of 5% to 7% would likely neutralize that possibility. All told, proportional representation appears to be an intriguing alternative to our present winner-take-all voting system

Throwing the rascals out? Problems of accountability in two-party systems

This article critically examines the concept of 'accountability' as it is understood in two-party systems and majoritarian democracy - namely the ability of voters to remove governments that violate their mandates or otherwise perform poorly. Voters' capacity to 'throw the rascals out' is one of the main normative appeals of two-partism and the single-member plurality (SMP) electoral system. However, this article uses a spatial model to show that in at least two types of situation voters are left in a bind when confronted with a mandate-breaking governing party: (1) when both major parties undertake unexpected non-centrist shifts in opposing directions after an election, leaving centrist voters with an unappealing choice; and (2) when a governing party that had won an election on a non-centrist platform undertakes a post-election shift to the centre, leaving its more radical supporters dissatisfied. In each case, voters have four imperfect options: punish the governing party by throwing the rascals out, but in doing so vote for a party that is ideologically more distant; abstain, and withdraw from the democratic process; vote for a minor party that has no hope of influencing government formation, but which might detach enough votes to allow the ideologically more distant major opposition party to win; and forgive the governing party its mandate-breaking. All of these options represent accountability failures. The problems are illustrated with two case studies from two-party systems: the United Kingdom in the mid-1980s and New Zealand in the period 1984-1993. In both instances, many voters found it difficult to 'throw the rascals out' without harming their own interests in the process. The article concludes that accountability may sometimes be better achieved if voters can force a party to share power in coalition with another party in order to 'keep it honest' instead of removing it from government completely, as can happen in multi-party systems based on proportional representation. Thus, although two-partism based on plurality voting is normally regarded as superior to multi-partism and proportional representation on the criterion of accountability, in some instances, the reverse can be true. The article therefore undermines a core normative argument advanced by supporters of majoritarian democracy and SMP