The Swing Voter’s Curse in the Laboratory

This paper reports the first laboratory study of the swing voter’s curse and provides insights on the larger theoretical and empirical literature on "pivotal voter" models. Our experiment controls for different information levels of voters, as well as the size of the electorate, the distribution of preferences, and other theoretically relevant parameters. The design varies the share of partisan voters and the prior belief about a payoff relevant state of the world. Our results support the equilibrium predictions of the Feddersen-Pesendorfer model, and clearly reject the notion that voters in the laboratory use naive decision-theoretic strategies. The voters act as if they are aware of the swing voter’s curse and adjust their behavior to compensate. While the compensation is not complete and there is some heterogeneity in individual behavior, we find that aggregate outcomes, such as efficiency, turnout, and margin of victory, closely track the theoretical predictions

UNIFORM SPERM MORPHOLOGY IN THE LEK-BREEDING WIRE-TAILED MANAKIN (PIPRA FILICAUDA)

Abstract ∙ When females copulate with multiple males, selection on spermatozoa can reduce variation in sperm morphology. We describe sperm morphology for a polygynous lek-breeding suboscine, the Wire-tailed Manakin (Pipra filicauda). Total sperm length averaged 41.5 ± 0.7 μm and the among-individual coefficient of variation in total sperm length was 1.8%. Variation was considerably lower than in the other manakin species with known sperm morphology, the Lance-tailed Manakin (Chiroxiphia lanceolata), despite similar promiscuity levels. This result highlights the need for further work on spermatozoa in lek-breeding species. Resumen ∙ Morfología uniforme en el esperma del Saltarín Uirapuru (Pipra filicauda), una especie con sistema de apareamiento de lek Cuando las hembras copulan con más de un macho, selección actuando al nivel del espermatozoide puede reducir la variación en la morfología del esperma. Aquí describimos la morfología del esperma para una especie poligínica de suboscín con sistema de apareamiento de lek, el Saltarín Uirapuru (Pipra filicauda). Los espermatozoides tuvieron una longitud total promedio de 41.5 ± 0.7 μm, y el coeficiente de variación para la longitud total fue de 1.8%. El nivel de variación fue menor que en la otra especie de saltarín estudiada al respecto, el Saltarín Lanceolado (Chiroxiphia lanceolata), aunque ambas especies tienen casi el mismo nivel de promiscuidad. Estos resultados sugieren la necesidad de más estudios sobre especies de aves con este sistema de apareamiento

Redesigning the Basic Communication Course: A Case Study

In the competitive environment of higher education, the basic communication course is under pressure to defend its place in the curriculum. One way to do this is to engage in a course redesign program. In this case study, we detail our experience taking part in such a program to (re)evaluate our course. Over the course of a year, we collected active participation data and conducted a series of three qualitative surveys that focused on student perceptions of our course. In doing so, we explored the ways in which the basic communication course can take advantage of course redesign efforts. Specifically, we found that we were better able to (1) articulate our unique course identity to constituents across the campus as we (2) developed a more holistic view of the ways we were (or were not) achieving our stated learning outcomes. Based on these findings, we developed practical implications including explicating how a well-planned course redesign program can be used in the basic communication course, the need for “collaborative consistency” when redesigning a course, and the imperative to incorporate student voice into redesign efforts

MultiBUGS: A Parallel Implementation of the BUGS Modeling Framework for Faster Bayesian Inference

MultiBUGS is a new version of the general-purpose Bayesian modeling software BUGS that implements a generic algorithm for parallelizing Markov chain Monte Carlo (MCMC) algorithms to speed up posterior inference of Bayesian models. The algorithm parallelizes evaluation of the product-form likelihoods formed when a parameter has many children in the directed acyclic graph (DAG) representation; and parallelizes sampling of conditionally-independent sets of parameters. A heuristic algorithm is used to decide which approach to use for each parameter and to apportion computation across computational cores. This enables MultiBUGS to automatically parallelize the broad range of statistical models that can be fitted using BUGS-language software, making the dramatic speed-ups of modern multi-core computing accessible to applied statisticians, without requiring any experience of parallel programming. We demonstrate the use of MultiBUGS on simulated data designed to mimic a hierarchical e-health linked-data study of methadone prescriptions including 425,112 observations and 20,426 random effects. Posterior inference for the e-health model takes several hours in existing software, but MultiBUGS can perform inference in only 28 minutes using 48 computational cores