Search

This paper evaluates three prominent voting systems: the Majority Rule (MR), Borda Rule (BR), and Plurality Rule (PR). Our analysis centers on the susceptibilities of each system to potential transgressions of two foundational principles: the respect for majority preference (majoritarianism) and the acknowledgment of the intensity of individual preferences. We operationalize the concept of 'cost' as the expected deviation from the aforementioned principles. A comparative assessment of MR, BR, and PR is undertaken in terms of their costs. Our findings underscore the superiority of PR over MR, whilst also highlighting the comparative advantage of MR against BR. [ABSTRACT FROM AUTHOR]

Instrumental variable methods are among the most commonly used causal inference approaches to deal with unmeasured confounders in observational studies. The presence of invalid instruments is the primary concern for practical applications, and a fast-growing area of research is inference for the causal effect with possibly invalid instruments. This paper illustrates that the existing confidence intervals may undercover when the valid and invalid instruments are hard to separate in a data-dependent way. To address this, we construct uniformly valid confidence intervals that are robust to the mistakes in separating valid and invalid instruments. We propose to search for a range of treatment effect values that lead to sufficiently many valid instruments. We further devise a novel sampling method, which, together with searching, leads to a more precise confidence interval. Our proposed searching and sampling confidence intervals are uniformly valid and achieve the parametric length under the finite-sample majority and plurality rules. We apply our proposal to examine the effect of education on earnings. The proposed method is implemented in the R package R o b u s t I V available from CRAN. [ABSTRACT FROM AUTHOR]

When a majority of voters has common values, but private information, then the runoff rule always admits an equilibrium that aggregates information strictly better than any equilibrium of the plurality rule. But there are cases in which the plurality rule supports equilibria that aggregate information strictly better compared to certain undominated equilibria of the runoff rule. Is there any risk with applying the runoff rule in these situations? We conduct a laboratory experiment and we show that the runoff rule consistently delivers better outcomes than the plurality rule even in such unfavorable scenarios. This establishes that the superiority of the runoff rule over the plurality rule in empirical settings outperforms its theoretical advantages. [ABSTRACT FROM AUTHOR]

We consider a collective choice problem in which the number of alternatives and the number of voters vary. Two fundamental axioms of consistency in such a setting, reinforcement and composition-consistency, are incompatible. We first observe that the latter implies four conditions each of which can be formulated as a consistency axiom on its own right. We find that two of these conditions are compatible with reinforcement. In fact, one of these, called composition-consistency with respect to non-clone winners, turns out to characterize a class of scoring rules which contains the Plurality rule. When combined with a requirement of monotonicity, composition-consistency with respect to non-clone winners uniquely characterizes the Plurality rule. A second implication of composition-consistency leads to a class of scoring rules that always select a Plurality winner when combined with monotonicity. [ABSTRACT FROM AUTHOR]

In this paper we study the distribution of power in the Basque Parliament since the restoration of the Spanish democracy. The classic simple games do not fit with the particular voting rule that it is used to invest the president of the regional government. In order to model this voting mechanism we incorporate coalitional externalities to the game. We use the extensions of the most popular power indices to games with externalities that have been proposed in the most recent literature. Moreover, we propose a method to estimate the probability of a given coalition based on the ideological positions of its members in a two-dimensional political spectrum. [ABSTRACT FROM AUTHOR]

In many countries, three or more candidates compete against one another in single-office elections. I present a model of three candidates competing for a single office in which two candidates can form a coalition prior to the election (a pre-electoral coalition). Since the candidates are both policy- and office-motivated, one candidate can incentivize the other candidate to withdraw his candidacy by choosing a joint policy platform. I examine how electoral environments such as election rules, ideological distance, and pre-election polls influence incentives to form pre-electoral coalitions. I find that pre-electoral coalitions are more likely to form (i) in plurality elections than in two-round runoff elections, (ii) as the threshold for first-round victory decreases in two-round runoff elections, (iii) as the two potential coalition partners' ideological distance increases, conditional on divided support, and (iv) as the fraction of office value which is transferable increases. Moreover, I analyze and compare voter welfare under plurality and the two-round runoff rules. • I build a model of three candidates competing for a single office. • Two candidates can form a coalition before the election. • In the model, both candidates and voters are strategic agents. • Pre-electoral coalitions are more likely to form in plurality elections than in two-round runoff elections. • I analyze how ideological distance and pre-election polls change incentives to form a pre-electoral coalition. [ABSTRACT FROM AUTHOR]

We study a general multiparty model of plurality rule elections with costly participation, and prove that strategic voting – that is, situations in which some voters abandon their most preferred alternative and vote strategically for the serious contender they dislike less – may emerge in equilibrium; just like when participation is costless/compulsory (Palfrey, 1989). This qualifies opposite claims made in more confined setups (e.g. Arzumanyan and Polborn, 2017), and establishes that Duverger's psychological effect is present in a much larger set of cases than currently believed. [ABSTRACT FROM AUTHOR]

Background: Alternative payment models frequently require attribution of patients to individual physicians to assign cost and quality outcomes. Our objective was to examine the performance of three methods for attributing a patient with cancer to the likeliest physician prescriber of anticancer drugs for that patient using administrative claims data. Methods: We used the HealthCore Integrated Research Environment to identify patients who had claims for anticancer medication along with diagnosis codes for breast, lung, or colorectal lung cancer between July 2013 and September 2017. The index date was the first date with a record for anticancer medication and cancer diagnosis code. Included patients had continuous medical coverage from 6 months before index to at least 7 days after index. Patients who received anticancer drugs during the 6 months prior to index were excluded. The three methods attributed each patient to the physician with whom the patient had the most evaluation and management (E&M) visits within a 90-day window around the index date (Method 1); the most E&M visits with no time window (Method 2); or the E&M visit nearest in time to the index date (Method 3). We assessed the performance of the methods using the percentage of the study cohort successfully attributed to a physician, and the positive predictive value (PPV) relative to available physician-reported data on patient(s) they treat. Results: In total, 70,641 patients were available for attribution to physicians. Percentages of the study cohort attributed to a physician were: Method 1, 92.6%; Method 2, 96.9%; and Method 3, 96.9%. PPVs for each method were 84.4%, 80.6%, and 75.8%, respectively. Conclusion: We found that a claims-based algorithm – specifically, a plurality method with a 90-day time window – correctly attributed nearly 85% of patients to a prescribing physician. Claims data can reliably identify prescribing physicians in oncology. [ABSTRACT FROM AUTHOR]