Inference for multivariate normal hierarchical models

This paper provides a new method and algorithm for making inferences about the parameters of a two-level multivariate normal hierarchical model. One has observed J p -dimensional vector outcomes, distributed at level 1 as multivariate normal with unknown mean vectors and with known covariance matrices. At level 2, the unknown mean vectors also have normal distributions, with common unknown covariance matrix A and with means depending on known covariates and on unknown regression coefficients. The algorithm samples independently from the marginal posterior distribution of A by using rejection procedures. Functions such as posterior means and covariances of the level 1 mean vectors and of the level 2 regression coefficient are estimated by averaging over posterior values calculated conditionally on each value of A drawn. This estimation accounts for the uncertainty in A , unlike standard restricted maximum likelihood empirical Bayes procedures. It is based on independent draws from the exact posterior distributions, unlike Gibbs sampling. The procedure is demonstrated for profiling hospitals based on patients' responses concerning p =2 types of problems (non-surgical and surgical). The frequency operating characteristics of the rule corresponding to a particular vague multivariate prior distribution are shown via simulation to achieve their nominal values in that setting.     

Corporate Foundations as Hybrid Organizations: A Systematic Review of Literature

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - The rise and global reach of the corporate foundation (CF) phenomenon has attracted the attention of academic researchers...     

Re-examining female labor supply responses to the 1994 Australian pension reform

Many governments are aiming to extend working lives by raising the age at which people can claim retirement pensions. This makes it vital to understand how these policies affect retirement decisions. In this paper, I revisit the labor supply effects of a major Australian reform that increased women’s pension age from 60 to 65. Atalay and Barrett (2015) studied these effects using repeated household surveys and a differences-in-differences design in which male cohorts form the comparison group. They estimate that the reform increased female labor force participation by 12 percentage points. Using earlier data, I show that the parallel-trends assumption did not hold before the reform because of a strong female-specific trend in participation rates across the relevant cohorts. Accounting for this trend, the estimated effect on female participation falls by two-thirds and becomes statistically insignificant at conventional levels. This highlights the importance of carefully assessing and controlling for trends across cohorts when evaluating pension reforms, which are typically phased in across cohorts.

     

Prevalence and risk factors of Leptospira infection in urban brown rats (Rattus norvegicus), Vienna,Austria

Urban Ecosystems - Leptospirosis is a worldwide bacterial zoonosis which incidence is expected to increase in conjunction with global change. In urban ecosystems, synanthropic rats are the key...     

INDUSTRY RESOURCE ALLOCATION TO BASIC RESEARCH UNDER NORMALLY DISTRIBUTED BENEFITS*

The failure of a free market system to attain socially optimal allocation of resources to research and development (R&D) is a generally recognized problem. However, we are just beginning to understand the types of R&D activities that receive relatively serious underinvestment from specific types of industries and the types of governmental intervention strategies that are likely to be effective and efficient in the correction of that underinvestment. Recently, Joglekar and Hamburg [16] [17] sought answers to these types of questions using models of the resource allocation behavior of firms considering investment in basic research related to their industry. It was assumed that the firms' benefits were exponentially distributed. In the present article, such benefits are assumed to be normally distributed, and an attempt is made to verify the earlier conclusions and policy implications of [16] and [17]. The results are similar for these two substantially different types of distribution, but the earlier conclusions and policy implications are clarified, qualified, and extended.     

Employment of Older People in the European Union

Abstract. This article identifies the alternative employment modes of older workers in the European Union. Against a background of changing levels of labour force participation and declining employment opportunities the paper describes and discusses the relative significance for older workers of alternative employment modes. Two atypical modes, part‐time and self‐employment, are discussed in detail. The paper concludes that atypical employment modes offer ageing employees the opportunity to gradually retire by providing a bridge between full‐time employment and final retirement.     

An Examination of Procedural and Object-oriented Systems Analysis Methods: Does Prior Experience Help or Hinder Performance?*

Interest in object-oriented analysis (OOA) and object-oriented design (OOD) has expanded rapidly over the last several years. Proponents of OOA and OOD have called the shift to these methods “revolutionary” and have cited a number of impressive claims with respect to their use. However, empirical research investigating these claims remains in its infancy. Moreover, an examination of the literature reveals inconclusive and often conflicting results for OOA and OOD methods relative to traditional data and/or procedural techniques. This paper presents the results of an empirical study that examined both experienced and novice systems analysts using both procedural and object-oriented techniques. This research examined whether experience in using procedural methods helped or hindered performance using OOA and compared procedural and OOA methods on the subjective mental workload induced. A human problem-solving model adopted from Newell and Simon (1972) provided the theoretical framework for this study. Dependent variables include subjective mental workload, solution quality, time to perform task, and attitudinal measures. Although some of these dependent variables have been used in past research, we believe this is the first time that subjective mental workload (SMW) has been examined in an IS context. Our results indicate that both novice and experienced subjects demonstrate higher SMW when using OOA. In addition, as a group, novices prefer object-oriented techniques and find these techniques easier as compared to experienced subjects.