A Sparse Implementation of the Average Information Algorithm for Factor Analytic and Reduced Rank Variance Models

Factor analytic variance models have been widely considered for the analysis of multivariate data particularly in the psychometrics area. Recently Smith, Cullis & Thompson (2001) have considered their use in the analysis of multi‐environment data arising from plant improvement programs. For these data, the size of the problem and the complexity of the variance models chosen to account for spatial heterogeneity within trials implies that standard algorithms for fitting factor analytic models can be computationally expensive. This paper presents a sparse implementation of the average information algorithm (Gilmour, Thompson & Cullis, 1995) for fitting factor analytic and reduced rank variance models.     

Optimal scaling of Metropolis algorithms: Heading toward general target distributions

The authors provide an overview of optimal scaling results for the Metropolis algorithm with Gaussian proposal distribution. They address in more depth the case of high‐dimensional target distributions formed of independent, but not identically distributed components. They attempt to give an intuitive explanation as to why the well‐known optimal acceptance rate of 0.234 is not always suitable. They show how to find the asymptotically optimal acceptance rate when needed, and they explain why it is sometimes necessary to turn to inhomogeneous proposal distributions. Their results are illustrated with a simple example.     

Some results on optimality in models with heteroscedastic errors from partial optimum designs

This paper studies optimum designs for linear models when the errors are heteroscedastic. Sufficient conditions are given in order to obtainD-, A- andE-optimum designs for a complete regression model from partial optimum designs for some sub-parameters. A result about optimality for a complete model from the optimality for the submodels is included. Supported by Junta de Andalucía, research group FQM244.     

A “brer rabbit” case for reverse mandated benefits

Reverse mandated benefits is a government-mandated policy that requires employees to provide their employers with benefits that workers would not provide otherwise. Of course, only those benefits would be mandated that are worth more to employers than they cost, as determined by political authorities. My case for such a policy argues that it is at least as sensible as policies mandating that employers provide benefits to their employees that would not be provided otherwise.     

Intertemporal choice under timing risk: An experimental approach

This paper investigates how individuals evaluate delayed outcomes with risky realization times. Under the discounted expected utility (DEU) model, such evaluations depend only on intertemporal preferences. We obtain several testable hypotheses using the DEU model as a benchmark and test these hypotheses in three experiments. In general, our results show that the DEU model is a poor predictor of intertemporal choice behavior under timing risk. We found that individuals are averse to timing risk and that they evaluate timing lotteries in a rank-dependent fashion. The main driver of timing risk aversion is nothing but probabilistic risk aversion that stems from the nonlinear treatment of probabilities.     

Violations of dominance in pricing judgments

The dominance principle states that the judged price of gamble A should be equal to or greater than the judged price of gamble B whenever A's outcomes are equal to or better than the corresponding outcomes of B, holding everything else constant. Subjects often violate the dominance principle by assigning a higher price to a gamble with some probability of winning a positive amount, Y, otherwise zero, than to a superior gamble with the same chances of winning Y, otherwise winning X. Violations also occur with losses. Results are consistent with a configural-weight theory in which the decision weight for each outcome depends on the rank of the outcome with respect to the other outcomes in the lottery and the value of the outcome (zero vs. nonzero).The authors thank Shi-jie Chang, Duncan Luce, and Lisa Ordóñez for comments on an earlier draft. This research was supported by a National Science Foundation grant to the first author (BNS-8451368). Requests for reprints should be sent to Barbara Mellers, Dept. of Psychology, University of California, Berkeley, CA 94720.     

First Nations and community economic development: a case study

A training project in a northern Canadian community providedan opportunity to examine participatory planning approachesand the meaning of work in First Nations communities. Focusgroups conducted three years after the unsuccessful interventionof a community economic development (CED) project suggest thatcomplex factors such as lack of support from community leadersand rate of pay for workers determine whether CED is alwaysappropriate in northern, First Nations contexts.     

The humorous construction of disability: 'stand-up' comedians in the United States

We examine how stand-up [sic] comedy constructs, circulates, perpetuates and/or disrupts stereotypical images of disabled persons in the United States. We use disabled people, rather than people-first language, to remind readers that disability is an ill-defined, culturally imposed attribute. Although humor is culturally specific, we draw on works of an international cadre of humanities scholars and social scientists to ground our analyses. We conclude that disability humor constitutes an emerging, liberatory art form. Disabled and non-disabled comedians elicit thought-provoking laughter and present disability as an interesting way to live. However, disabling humor still perpetuates stereotyping and isolation.     

Four‐Month‐Olds' Discrimination of Voice Changes in Multimodal Displays as a Function of Discrimination Protocol

Past studies have found equivocal support for the ability of young infants to discriminate infant‐directed (ID) speech information in the presence of auditory‐only versus auditory + visual displays (faces + voices). Generally, younger infants appear to have more difficulty discriminating a change in the vocal properties of ID speech when they are accompanied by faces. Forty 4‐month‐old infants were tested using either an infant‐controlled habituation procedure (Experiment 1) or a fixed‐trial habituation procedure (Experiment 2). The prediction was that the infant‐controlled habituation procedure would be a more sensitive measure of infant attention to complex displays. The results indicated that 4‐month‐old infants discriminated voice changes in dynamic face + voice displays depending on the order in which they were viewed during the infant‐controlled habituation procedure. In contrast, no evidence of discrimination was found in the fixed‐trial procedure. The findings suggest that the selection of experimental methodology plays a significant role in the empirical observations of infant perceptual abilities.