If you like the alternative vote (a.k.a. the instant runoff), then you ought to know about the Coombs rule

We consider four factors relevant to picking a voting rule to be used to select a single candidate from among a set of choices: (1) avoidance of Condorcet losers, (2) choice of Condorcet winners, (3) resistance to manipulability via strategic voting, (4) simplicity. However, we do not try to evaluate all voting rules that might be used to select a single alternative. Rather, our focus is restricted to a comparison between a rule which, under the name ‘instant runoff,’ has recently been pushed by electoral reformers in the US to replace plurality-based elections, and which has been advocated for use in plural societies as a means of mitigating ethnic conflict; and another similar rule, the ‘Coombs rule.’ In both rules, voters are required to rank order candidates. Using the instant runoff, the candidate with the fewest first place votes is eliminated; while under the Coombs rule, the candidate with the most last place votes is eliminated. The instant runoff is familiar to electoral system specialists under the name ‘alternative vote’ (i.e., the single transferable vote restricted to choice of a single candidate). The Coombs rule has gone virtually unmentioned in the electoral systems literature (see, however, Chamberlin et al., 1984). Rather than considering the properties of these two rules in the abstract, we evaluate them in the politically realistic situations where voters are posited to have (at least on balance) single-peaked preferences over alternatives. Evaluating the two rules under this assumption, we argue that the Coombs rule is directly comparable in that Coombs is always as good as AV with respect to two of our four criteria and it is clearly superior to AV with respect to one of the four criteria, namely criterion (2), and is potentially inferior only with respect to criterion (3). Key to this argument are two new propositions. The first new result shows that, under the posited assumption, for four alternatives or fewer, AV is always as likely or more likely to select the Condorcet winner than plurality. The second new result shows that, under the same assumptions, the Coombs rule will always select the Condorcet winner regardless of the number of alternatives.     

Nash equilibrium strategies in directional models of two- candidate spatial competition

The standard approach to two-party political competition in a multi-dimensional issue space models voters as voting for the alternative that is located closest to their own most preferred location. Another approach to understanding voter choice is based on preferred direction of change with respect to some specified neutral point (e.g., an origin or status quo point). For the two-dimensional Matthews directional model (Matthews, 1979), we provide geometric conditions in terms of the number of medians through the neutral point for there to be a Condorcet (undominated) direction. In this two-dimensional setting, the set of residual locations for which no Condorcet directions exist is identical to the null dual set (Schofield, 1978) and to the heart (Schofield, 1993). In two dimensions, for most locations of the origin/status quo point, a Condorcet direction exists and points toward the yolk, a geometric construct first identified by McKelvey (1986). We also provide some simulation results on the size of the null dual set in two dimensions when the underlying distribution of points is non-symmetric.     

Rethinking the partisan effects of higher turnout: So what's the question?

Controversy persists over the link between turnout and the likelihood of success of Democratic candidates (e.g., DeNardo, 1980, 1986; Zimmer, 1985; Tucker and Vedlitz, 1986; Piven and Cloward, 1988; Texeira, 1992; Radcliff, 1994, 1995; Erikson, 1995a, b). We argue that the authors in this debate have largely been talking past one another because of a failure to distinguish three quite different questions. The first question is: “Are low turnout voters more likely to vote Democratic than high turnout voters?” The second question is: “Should we expect that elections in which turnout is higher are ones in which we can expect Democrats to have done better?” The third question is the counterfactual: “If turnout were to have increased in some given election, would Democrats have done better?” We show the logical independence of the first two questions from one another and from the third, and argue that previous researchers have failed to recognize this logical independence – sometimes thinking they were answering question three when in fact they were answering either question one or question two. Reviewing previous research, we find that the answer to the first question once was YES but, for more recent elections at the presidential level, now appears to be NO, while, for congressional and legislative elections, the answer to the second question appears generally to be NO. However, the third question is essentially unanswerable absent an explicit model of why and how turnout can be expected to increase, and/or analyses of individual level panel data. Thus, the cross-sectional and pooled data analyses of previous research are of almost no value in addressing this third question.

     

Digital dental radiographic identification in the pediatric, mixed and permanent dentitions.

The purpose of this paper is to investigate the utility of digital dental radiographic superimposition in the various stages of development of the human dentition. Digital, computer assisted dental identification is a means of identification which allows the spatial relationships of the root and support structures of the teeth to be compared one to the other. The technique has not been tested in patients with developing dentitions. Dental radiographs from patients in the pediatric, mixed and permanent dentition stages of development, simulating "antemortem" and "postmortem" radiographs, were digitized using a flat field radiograph scanner. Anatomic features were used as points of comparison utilizing image editing software whereby anatomic sections were digitally cut from the antemortem image and compared to the same anatomic locations on the postmortem image to assess for points of concordance. The technique was applied to 25 cases within the primary dentition, 25 cases within the mixed dentition and 25 cases within the permanent dentition. Results showed that this was a viable technique within both the pediatric and permanent dentition although it was of little value within the mixed dentition.     

Centripetal forces in spatial voting: On the size of the Yolk

The yolk, the smallest circle which intersects all median lines, has been shown to be an important tool in understanding the nature of majority voting in a spatial voting context. The center of the yolk is a natural ‘center’ of the set of voter ideal points. The radius of the yolk can be used to provide bounds on the size of the feasible set of outcomes of sophisticated voting under standard amendment procedure, and on the limits of agenda manipulation and cycling when voting is sincere. We show that under many plausible conditions the yolk can be expected to be small. Thus, majority rule processes in spatial voting games will be far better behaved than has commonly been supposed, and the possible outcomes of agenda manipulations will be generally constrained. This result was first conjectured by Tullock (1967).     

The Conservative Member of Parliament as Lobbyist for Constituency Economic Interests

Interviews undertaken in the House of Commons with 70 backbench Conservative MPs in 1983–84 examined the extent to which they pursue their own localized industrial policy strategies as part of their efforts to maintain constituency electoral support. This involves lobbying efforts directed toward ministers in support of local industries, either in defence of jobs, in promotion of new jobs, or in a variety of quests for government benefits or relaxation of restrictions. It was found that 36 of the 70 Conservative MPs could be classified as 'constituency lobbyists', reflecting interview evidence that they consider lobbying on behalf of local industries to be a normal and important part of their representative role as MPs. The hypothesis that vulnerable constituencies—vulnerable in both political and economic terms—would be represented by constituency lobbyists was tested through the construction of an index of constituency 'security'. It was found that the more secure the constituency, the less likely is the MP to lobby on behalf of local industrial interests.     

ORO. The Physical Developer replacement?

In the process of fingerprint development Physical Developer has been largely the method of choice on porous surfaces after coming into contact with wet environments. It is only recently that a new technique has been identified which could replace this standard technique. This study aims to build on previous research and expand knowledge regarding the technique. The study built on previous research and compared Physical Developer to Oil Red O, testing both on four paper types, while being placed in three different water types and an accelerant for various amounts of time. Marks were placed with both heavily ‘loaded’ sebaceous fingers and ‘normal’ un-washed fingers. Results show that Oil Red O consistently produced clearer more detailed marks from the ‘loaded’ fingers, but neither technique proved to work better on the ‘normal’ marks. Neither technique developed any prints from the accelerant.