A Note on the Poisson Likelihood Ratio Test Statistic for Kulldorff's Scan Methods

Methods based on scan statistics are widely used in health-related applications to detect clusters of disease. The most common methods are based on the Bernoulli and Poisson models. Kulldorff (1997 Kulldorff , M. ( 1997 ). A spatial scan statistic . Communications in Statistics—Theory and Methods 26 : 1481 – 1496 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) derived the likelihood ratio test statistic for his scan method for both of these models. His scan statistic is widely used with freely available software, SaTScan^? (see Kulldorff, 2005 Kulldorff , M. ( 2005 ). SaTScan: software for the spatial, temporal, and space-time scan statistics , version 5.1 [computer program]. Information Management Services 2005; Available: http://www.satscan.org/. Accessed July 2007 . [Google Scholar]). We provide an alternative derivation of the likelihood ratio test statistic in the Poisson case. Our derivation is simpler and more general in the sense that it applies when the incidences are not aggregated into subregional counts.     

A Review of the packing problem

The random pazking problem has been of interest to inoestigsccrs in seveal disciplines , Physical chemists have investigaced such models in two and three dimensions, Because of aralytical difficulties, one-dimensional analogacs have been explored and theseare referred to as the parking problem, A number of results areexplored and attempts are made to tie them together, Applicationsare also highlighted.     

Generalized least squares estimation of multivariate nonlinear models with missing data

The method of estimated generalized least squares estimation of multiple response models is extended to the randomly missing date case. This estimation procedure is computationally simply when there are many missing data but the number of distinct patterns of missing data for the response vectors is small. The consistency and asymptotic normality of the proposed estimators are established.     

Meta-cognition and resistance to political persuasion: evidence from a three-wave panel study

ABSTRACT

We investigate the temporal course of meta-cognition and resistance processes following exposure to counter-attitudinal information in the 2012 Presidential election. Using a unique 3-wave survey panel design, we tracked eligible voters during the last months of the 2012 campaign and experimentally manipulated exposure to negative political messages targeting Barack Obama and Mitt Romney on an online platform. As predicted, we found that politically unengaged (vs. engaged) individuals were less likely to counter-argue a message attacking their favored candidate. Resistance, in turn, led to increased attitudinal certainty, polarization, and correspondence with actual voting behavior over the course of the campaign. These findings provide the first analysis of the longitudinal effects of meta-cognitive processes underlying persuasion for real-world attitude change and behavior.     

Compliance Strategies and Regulatory Effectiveness of Performance-Based Regulation of Chemical Accident Risks

This paper investigates the role that performance-based regulations can play in linking a firm's environmental, health, and safety concerns with their corporate strategy. The specific focus is on the performance standards required by the Clean Air Act Amendments (CAAA) which require firms that store or use certain chemicals to develop a Risk Management Plan (RMP) for reducing the likelihood and impact of accidents at their plants. Data from a series of case studies and interviews of executives in chemical firms reveal that proactive companies integrated many of the requirements of the CAAA into their management systems prior to the regulatory requirements. Most of these firms tend to be large ones. Small firms often lack the resources to implement these regulations and hence have tended to have a more difficult time with compliance.     

Competence and Competitive Advantage: Towards a Dynamic Model

Over the last ten years the concept of ‘competence’ has emerged as a central concept for competitive strategy. Several rich theoretical streams have contributed an extensive array of frameworks, definitions and papers using the concept. There is now a need to integrate these many contributions. Indeed, some of the frustration expressed recently by academics may be due to the large volume of conversation and the low level of integration. A concept that is considered so useful that many writers have incorporated it in their work will be of little value if it takes on different meanings for every use. If competence is to be used to explain relationships among variables and to build richer understandings of the roots of competitive advantage, then the field needs to engage in a serious conversation that attempts to focus this concept. Competence needs to be understood in a way that is faithful to its theoretical roots, allows the multiple dimensions that underpin competitive advantage to be meaningfully integrated and is specific enough that meaningful differences can emerge when used as a variable in empirical research. This paper seeks to begin a conversation toward that end by presenting a conceptualization that meets all of these requirements. The paper builds its conceptualization around satisfying the elements of a dynamic model of the relationship between competence and competitive advantage.     

The problems of eligibility and endogenous confounders when assessing the mortality impact of a nationwide disease-prevention programme: the case of insecticide-treated nets in Togo

Evaluation of the mortality impact of nationwide disease-prevention efforts is complicated by potential endogeneity: programme recipients may have unobserved characteristics that simultaneously make them both more likely to become recipients and more likely to survive as a result of other health practices. This population-based study assesses the mortality impact of a nationwide programme that distributed insecticide-treated nets (ITNs) to mothers of children aged 9-59 months in Togo. By comparing mortality rates before and after the programme according to households' eligibility status, we demonstrate that a one-time programme that restricts eligibility to households with a surviving child excludes some households with a high risk of child mortality. We then apply simultaneous estimation models to untangle the mortality impact of ITNs from the effects of unobserved confounders and show that among eligible households, living in a household with ITNs significantly reduces mortality for children aged 20-59 months, even after controlling for endogeneity.     

Social relationships and shifting languages in Northern Thailand1

This paper explores how speakers’ understandings of the conduct of social relationships mediate changing and socially distinctive syncretic language practices in a Northern Thai community. Although a shift away from vernacular (Kam Muang) speech styles to Standard Thai was emblematically tied to young and urban speakers in nostalgic discourses, syncretic speech styles and metalinguistic discourses also reflected local and socially positioned understandings of institutional roles and social relationships. I argue that scholars of language change and shift should foreground the mediating role of social relationships in speakers’ uses and understandings of their communicative repertoires across multiple timescales.