Bayesian estimation in a U.S. government survey of income using respondent generated intervals S James Press University of California at Riverside U.S.A. Abstract This paper presents some preliminary results of a U.S. Census Bureau research survey of income in a national household sample. The survey questionnaire contained Respondent Generated Intervals (RGI) questions requesting bounds on the estimates of items recalled. A two-stage Bayesian hierarchical model was used to estimate population means for selected income-related items. Questionnaire design and testing was carried out as a joint effort of statisticians and cognitive scientists using the laboratory facilities of the U.S. Census Bureau. A Markov Chain Monte Carlo Gibbs sampler was used to find numerical Bayesian estimates of population parameters Keywords: Address for Correspondance: S. James Press Tel. (909) 787-4241 Fax (909) 787-3286 e-mail: jpress@ucrac1.ucr.edu Bayesian Methods for Monitoring a Comprehensive Test Ban Treaty Robert H. Shumway Division of Statistics University of California, Davis U.S.A. Abstract In preparation for monitoring the proposed Comprehensive Test Ban Treaty (CTBT), signed by a majority of nations, a global array of sensors producing seismic, acoustic, and radionuclide data is being developed that will forward data to a Prototype International Data Center (PIDC) for analysis. Two problems of special interest to the monitoring community are (1) the location of a presumed nuclear test and (2) the estimated yield produced by that test. Because there will be potential violations in uncalibrated regions and data from given event may be quite limited, it is natural to exploit the advantages available from introducing specified prior distributions and a Bayesian perspective. We develop posterior probability ellipses for location, based on a nonlinear regression relating estimated wave-number coordinates from several infrasound arrays to an unknown location. For seismic yield estimation, the posterior predictive distribution of a vector magnitude is inverted, using a multivariate regression model with joint normal -Wishart priors. The methods are applied to the 1998 nuclear tests carried out by India and Pakistan. Keywords: Calibration, predictive Bayes, nonlinear regression, yield estimation, event location Address for correspondence: Robert H. Shumway, Division of Statistics, University of California, Davis, CA 95616, U.S.A. e-mail: shumway@wald.ucdavis.edu web site: www.stat.ucdavis.edu/~shumway Bayesian Modeling of Economies and Data Requirements Arnold Zellner and Bin Chen Graduate School of Business University of Chicago and Abstract In previous work, we have used Bayesian methods in the analysis of various models to explain and forecast growth rates of real output (GDP) of 18 industrialized countries. Using these models, point and turning point forecasts were calculated and found to be reasonably accurate compared to those of benchmark and other models' forecasts. In current work, Marshallian demand, supply and entry relations have been formulated for major sectors of economics along with factor market models for input variables to provide a new Marshallian macroeconomic model (MMM). These sectoral models are being employed using data for the U.S. to provide various shrinkage and non-shrinkage Bayesian forecasts of sectoral outputs. These sectoral output forecasts are summed to provide a forecast of total output that is compared to past and recent forecasts of aggregate output using models for aggregate output. Theoretical and empirical results indicate that it pays to disaggregate. Some overall properties of the MMM will be described. In addition, data requirements for implementing current and future MMMs will be discussed. Keywords: Address for correspondence: Arnold Zellner H.G.B. Alexander Dist. Service Prof. Emeritus of Economics and Statistics 1101 E. 58 St., Chicago, IL 60637 e-mail: arnold.zellner@gsb.uchicago.edu web site: http://gsbwww.uchicago.edu/fac/arnold.zellner/index.html Twenty five years of Bayesian Inference in Psychology Henry Rouanet Centre de Recherche en Informatique de Paris 5 Universitι Renι Descartes France Abstract Since 1974, a great deal of Bayesian research has been conducted at the Universite Rene Descartes in close connection with psychological applications. The constant objective of this research has been to complement the conventional statistical tools by providing sensible and practical answers to major methodological issues such as assessing importance of effects, especially in ANOVA (see Lecoutre's paper) and categorized data (see Bernard's paper). Landmarks of this research are: Rouanet, Lepine, Pelnard-Considere (1976) in Advances in psychological and Educational Measurement (Wiley); Rouanet, Lepine, Holender (1978) in Attention & Performance VII; Rouanet, Lecoutre (1983) in Brit. J. Math. Psych.; Rouanet (1996) in Psychological Bulletin; Rouanet, Bernard, Bert, B. Lecoutre, M.P. Lecoutre, Le Roux with a Foreword by P. Suppes (1998) New ways in statistical methodology (Peter Lang). Address for correspondence: e-mail: Henry.Rouanet@math-info.univ-paris5.fr web site: Bayesian Analysis of Contingency Tables: Applications to Developmental Psychology Jean-Marc Bernard Laboratoire Cognition et Activites Finalisees University Paris 8 & CNRS France Abstract We present a series of Bayesian data analysis methods (Bernard, Charron, 1996a and 1996b, Math. Inf. Sci. Hum., 134, pp. 5-38 and 135, pp. 5-18; Danis, Bernard, Leproux, in press, Brit. J. Devel. Psych.) which all aim at analyzing local dependencies within an AxB contingency table and thus allow a detailed investigation of the direction of association, rather than merely focussing on the global dichotomy "independence vs. association". A basic idea in these methods is to confront the observed data with some specific association model which may be either a logical model -- which predicts the absence of some cells in the table --, or a less strong model -which only predicts some particular pattern of over-/under-representation of the cells in the table. These two kinds of issues are illustrated with experimental data from Developmental Psychology research (experimental investigation of the Piaget's stage concept, sequential analysis of adult/child interactions in a situation of picture-book reading). The methods combine descriptive and inductive aspects. At the descriptive level, the existence and the strength of local association is measured by several related association indices: association rates, mean association rates, implicative indices, and the "Del" index proposed by Hildebrand, Laing & Rosenthal (1977, Prediction Analysis of Cross Classifications, Wiley). The inductive step -- generalizing the descriptive conclusions to a larger population (multinomial sampling) -- is envisaged from an "objective" Bayesian viewpoint using either standard non-informative Dirichlet priors or the imprecise Dirichlet model (Walley, 1996, JRSS B, 58, pp. 5-37). We stress the high flexibility of the Bayesian approach to inference, in the sense that it enables one to investigate the generalisability of any conclusion emerging from the descriptive step, and, in particular here, one that states that the data support some particular association model of interest. Finally, we briefly describe some recent extensions to the analysis of higher dimensional contingency tables (Bernard, to appear, J. Stat. Plann. Inf.). Keywords: Measure of association, Logical model, Quasi-implication, Association model, Noninformative prior, Imprecise Dirichlet model. Address for correspondence: Jean-Marc Bernard Laboratoire Cognition et Activites Finalisees CNRS ESA 7021 Universite Paris 8 2 rue de la Liberte 93526 Saint-Denis Cedex France e-mail: berj@univ-paris8.fr Bayesian predictive procedures for designing and planning experiments Bruno Lecoutre C.N.R.S. Universit de Rouen France Abstract In recent years many authors have stressed the interest of the Bayesian predictive approach for designing ("how many subjects?") and monitoring ("when to stop?") experiments. The predictive distribution of a test statistic can be used to include and extend the frequentist notion of power in a way that has been termed predictive power or expected power. More generally, Bayesian predictive procedures give the researcher a very appealing method to evaluate the chances that the experiment will end up showing a conclusive result, or on the contrary a non-conclusive result. The prediction can be explicitly based on either the hypotheses used to design the experiment, expressed in terms of the prior distribution, or on partial available data, or on both. Keywords:Experimental data monitoring, Predictive distributions, Sample size determination, Stochastic curtailment, Average power. Address for correspondence: Bruno Lecoutre, UPRESA 6085, Analyse et Mod?les Stochastiques, C.N.R.S. et Universit? de Rouen, Math?matiques, Site Colbert, 76821 Mont-Saint-Aignan Cedex, France. e-mail: bruno.lecoutre@univ-rouen.fr Perfect sampling of Bayesian mixtures Duncan Murdoch and Xiao-Li Meng Department of Statistical and Actuarial Sciences University of Western Ontario Canada and Department of Statistics University of Chicago U.S.A. Abstract Perfect sampling using the coupling from the past (CFTP) algorithm was introduced by Propp and Wilson in 1996. In much the way rejection sampling allows one to convert samplers from one distribution into samplers from another, CFTP allows one to convert Markov chain Monte Carlo algorithms from approximate samplers from the steady-state distribution into perfect ones. Since 1996 CFTP has been applied to many different Markov chains. In this paper we describe our work applying it to Bayesian mixture priors and mixture likelihoods Keywords: Coupling from the past, perfect sampling, mixtures. Address for correspondence: Duncan Murdoch, Dept. of Stat. and Act. Sci, University of Western Ontario, London, ON N6A 5B7 Canada e-mail: murdoch@stats.uwo.ca web site: http://www.stats.uwo.ca/murdoch Perfect MCMC tempering for sample-based Bayesian inference Jesper Moeller and Geoff Nicholls Department of Mathematical Statistics Aalborg University Denmark and Department of Mathematics University of Auckland New Zealand Abstract Perfect simulation algorithms based on Propp and Wilson (1996) have so far been of limited use for sampling problems of interest in statistics. We specify a new family of perfect sampling algorithms obtained by combining MCMC tempering algorithms with dominated coupling from the past, and demonstrate that our algorithms will be useful for sample based inference. Keywords: Dominated coupling; Exact sampling; MCMC; tempering. Address for correspondence: Geoff Nicholls, Mathematics Department, Auckland University, Private Bag 92019, Auckland, New Zealand e-mail: nicholls@math.auckland.ac.nz web site: http://www.math.auckland.ac.nz/~nicholls/ Parallel Antithetic Coupling for Perfect Bayesian Simulation Xiao-Li Meng and Radu V. Craiu Department of Statistics The University of Chicago USA Abstract Constructing efficient perfect simulation algorithms has been a very active area of research since the innovative work of Propp and Wilson (1996). In this talk we propose the use of antithetic variates in parallel implementation of perfect simulation, aiming for substantial reduction of Monte Carlo error with little increase in computational load. We will discuss various methods for generating antithetic variates, in particularly the iterative hypercube sampling method, which incidentally generates a set of intriguing fractals. The theory of negative association, which studies the preservation of negative correlation under monotone transformations, will be central in our constructions. To illustrate the potential of our method in perfect Bayesian simulation, we apply it to perfect sampling from the posterior distribution of the mixing parameter when the prior belongs to the beta family. Keywords: antithetic variates, negative association, hypercube sampling, backward coupling, mixture model. Address for correspondence: Xiao-Li Meng, 5734 S University Ave., Chicago, Il 60637, U.S.A. e-mail: meng@galton.uchicago.edu web site: http://galton.uchicago.edu