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Rich Data Set (rich + data_set)
Selected AbstractsSpatial integration at multiple scales: rice markets in MadagascarAGRICULTURAL ECONOMICS, Issue 3 2009Christine Moser Market integration; Prices; Rice Abstract The dramatic increase in the price of rice and other commodities over the past year has generated new interest in how these markets work and how they can be improved. This article uses an exceptionally rich data set to test the extent to which markets in Madagascar are integrated across space at different scales of analysis and to explain some of the factors that limit spatial arbitrage and price equalization within a single country. We use rice price data across four quarters of 2000,2001 along with data on transportation costs and infrastructure availability for nearly 1,400 communes in Madagascar to examine the extent of market integration at three different spatial scales,subregional, regional, and national,and to determine whether non-integration is due to high transfer costs or lack of competition. The results indicate that markets are fairly well integrated at the subregional level and that factors such as high crime rates, remoteness, and lack of information are among the factors limiting competition. [source] Does government funding alter nonprofit governance?JOURNAL OF POLICY ANALYSIS AND MANAGEMENT, Issue 3 2002Evidence from New York City nonprofit contractors Government contracting has raised a collection of issues with respect to adequate oversight and accountability. This paper explores one avenue through which contracting agencies may achieve these tasks: through the governance practices of the contractor's board. Oversight and monitoring are a board's key responsibilities, and influencing a board's practices is one way a governmental agency can help to insure quality performance. Agencies could thus use both their selection process and their post-contracting power to influence board practice. Using a new, rich data set on the nonprofit contractors of New York City, a series of hypotheses were tested on the relationship between government funding and board practices. Significant differences were found to exist in board practices as a function of government funding levels, differences that mark a shift of energy away from some activities (i.e., traditional board functions, such as fund-raising) towards others (financial monitoring and advocacy). This suggests that government agencies may indeed use their contracting choices with an eye to particular governance practices. This increased emphasis on such activities appears to crowd out other activities, and is not unambiguously to the benefit of nonprofit board governance. © 2002 by the Association for Public Policy Analysis and Management. [source] WHO/ISBRA Study on State and Trait Markers of Alcohol Use and Dependence: Analysis of Demographic, Behavioral, Physiologic, and Drinking Variables That Contribute to Dependence and Seeking TreatmentALCOHOLISM, Issue 7 2002Jason Glanz Background Discussions between the World Health Organization (WHO) and the International Society on Biomedical Research on Alcoholism (ISBRA) identified the need for a multiple-center international study on state and trait markers of alcohol abuse and alcohol dependence. The reasoning behind the generation of such a project included the need to understand the alcohol use characteristics of diverse populations and the performance of biological markers of alcohol use in a variety of settings throughout the world. A second major reason for initiating this study was to collect DNA for well-structured and stratified association studies between genetic markers and/or "candidate" genes and behavioral/physiological phenotypes of importance to predisposition to alcohol dependence. Methods An extensive interview instrument was developed with leadership from the U.S. National Institute on Alcohol Abuse and Alcoholism (NIAAA). The instrument was translated from English to Finnish, French, German, Japanese, and Portuguese (Brazilian). One thousand eight hundred sixty-three subjects were recruited at five clinical centers (Montreal, Canada; Helsinki, Finland; Sapporo, Japan; São Paulo, Brazil; and Sydney, Australia). The subjects responded to the structured interview and provided blood and urine samples for biochemical analysis. This article focuses on the demographic characteristics of the study subjects, their drinking habits, alcohol-dependence characteristics, comorbid psychiatric and other drug variables, and predictors for seeking treatment for alcohol dependence. Multiple logistic regression models were constructed and used to explore variables that contribute to various levels of alcohol consumption, to a diagnosis of alcohol dependence, and to seeking treatment for alcohol dependence. ANOVA with post hoc comparisons, ,2, and Pearson moment calculations were used as necessary to assess additional relationships between variables. Results A number of factors previously noted in disparate studies were confirmed in our analysis. Men consumed more alcohol than women, Asians consumed less alcohol than whites or Blacks, alcohol-dependent subjects consumed more alcohol than nondependent subjects, alcohol consumption increased with age, and an increased level of education (university or postgraduate education) reduced the percentage of such individuals in the category designated as heavy drinkers (>210 g alcohol/week) and in the group who were currently in treatment for dependence. However, our analysis allowed for much more detailed comparisons; for example, although men drank more than women on a g/day basis, the differences were less pronounced on g/kg/day basis, and alcohol-dependent women drank equal amounts of alcohol as alcohol-dependent men on a g/kg/day basis. Antisocial personality characteristics or reports of trouble sleeping when an individual stops drinking were associated with higher alcohol intake. The most important of the tested factors that contributed to a DSM-IV diagnosis of dependence, however, was the report of anxiety if an individual stopped drinking. In terms of the various criteria within the DSM-IV criteria for alcohol dependence, no one criterion seemed to be prominent for individuals who sought alcohol dependence treatment, but the higher the number of criteria met by the individual, the higher was the probability that he or she would be in treatment. Conclusions This initial report is the beginning of the "data mining" of this rich data set. The cross-national/cross-cultural aspects of this study allowed for multiple comparisons of variables across several ethnic/racial groups and allowed for assessment of biochemical markers for alcohol intake and predisposition to alcohol dependence in diverse settings. [source] Joint projections of temperature and precipitation change from multiple climate models: a hierarchical Bayesian approachJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES A (STATISTICS IN SOCIETY), Issue 1 2009Claudia Tebaldi Summary., Posterior distributions for the joint projections of future temperature and precipitation trends and changes are derived by applying a Bayesian hierachical model to a rich data set of simulated climate from general circulation models. The simulations that are analysed here constitute the future projections on which the Intergovernmental Panel on Climate Change based its recent summary report on the future of our planet's climate, albeit without any sophisticated statistical handling of the data. Here we quantify the uncertainty that is represented by the variable results of the various models and their limited ability to represent the observed climate both at global and at regional scales. We do so in a Bayesian framework, by estimating posterior distributions of the climate change signals in terms of trends or differences between future and current periods, and we fully characterize the uncertain nature of a suite of other parameters, like biases, correlation terms and model-specific precisions. Besides presenting our results in terms of posterior distributions of the climate signals, we offer as an alternative representation of the uncertainties in climate change projections the use of the posterior predictive distribution of a new model's projections. The results from our analysis can find straightforward applications in impact studies, which necessitate not only best guesses but also a full representation of the uncertainty in climate change projections. For water resource and crop models, for example, it is vital to use joint projections of temperature and precipitation to represent the characteristics of future climate best, and our statistical analysis delivers just that. [source] Modelling species diversity through species level hierarchical modellingJOURNAL OF THE ROYAL STATISTICAL SOCIETY: SERIES C (APPLIED STATISTICS), Issue 1 2005Alan E. Gelfand Summary., Understanding spatial patterns of species diversity and the distributions of individ-ual species is a consuming problem in biogeography and conservation. The Cape floristic region of South Africa is a global hot spot of diversity and endemism, and the Protea atlas project, with about 60 000 site records across the region, provides an extraordinarily rich data set to model patterns of biodiversity. Model development is focused spatially at the scale of 1, grid cells (about 37 000 cells total for the region). We report on results for 23 species of a flowering plant family known as Proteaceae (of about 330 in the Cape floristic region) for a defined subregion. Using a Bayesian framework, we developed a two-stage, spatially explicit, hierarchical logistic regression. Stage 1 models the potential probability of presence or absence for each species at each cell, given species attributes, grid cell (site level) environmental data with species level coefficients, and a spatial random effect. The second level of the hierarchy models the probability of observing each species in each cell given that it is present. Because the atlas data are not evenly distributed across the landscape, grid cells contain variable numbers of sampling localities. Thus this model takes the sampling intensity at each site into account by assuming that the total number of times that a particular species was observed within a site follows a binomial distribution. After assigning prior distributions to all quantities in the model, samples from the posterior distribution were obtained via Markov chain Monte Carlo methods. Results are mapped as the model-estimated probability of presence for each species across the domain. This provides an alternative to customary empirical ,range-of-occupancy' displays. Summing yields the predicted richness of species over the region. Summaries of the posterior for each environmental coefficient show which variables are most important in explaining the presence of species. Our initial results describe biogeographical patterns over the modelled region remarkably well. In particular, species local population size and mode of dispersal contribute significantly to predicting patterns, along with annual precipitation, the coefficient of variation in rainfall and elevation. [source] Spatial patterns of inventors' mobility: Evidence on US urban areasPAPERS IN REGIONAL SCIENCE, Issue 2 2010Stefano Breschi Inventor; mobility; knowledge spillovers; geographical proximity Abstract This paper aims at contributing to the research on knowledge spillovers and their spatial extent by presenting new empirical evidence on a key mechanism driving and directing knowledge diffusion processes, namely, the mobility of knowledge and highly-skilled workers. The analysis is based on a rich data set on US inventors and their patents filed at the European Patent Office from 1978 to 2004. Findings indicate that two distinctive spatial patterns can be detected: inventors move both at short and large spatial distances (i.e., three hours and more than 8 hours driving distance, respectively) in similar proportions. Interestingly, in the largest innovative urban areas inventors' inflows and outflows primarily involve distant rather than neighbour areas. Resumen El objetivo de este artículo es contribuir a la investigación sobre spillovers de conocimiento y su amplitud espacial ya que presenta nuevas pruebas empíricas sobre un mecanismo clave para impulsar y dirigir los procesos de difusión de conocimiento, concretamente la movilidad de conocimiento y de mano de obra altamente especializada. El análisis está basado en un conjunto de datos exhaustivo sobre inventores estadounidenses y las patentes inscritas por ellos en la Oficina Europea de Patentes desde 1978 a 2004. Los resultados indican que se pueden detectar dos patrones espaciales distintivos: los inventores se mueven tanto a distancias cortas como largas (concretamente tres horas y más de ocho horas en automóvil, respectivamente) en proporciones similares. Es interesante mencionar que, en las áreas urbanas innovadoras más grandes, los flujos de entrada y salida de inventores están asociados principalmente a áreas lejanas en vez de a áreas vecinas. [source] Voter Decision Making in Election 2000: Campaign Effects, Partisan Activation, and the Clinton LegacyAMERICAN JOURNAL OF POLITICAL SCIENCE, Issue 4 2003D. Sunshine Hillygus How do citizens respond to campaign events? We explore this question with a unique repeated measures survey design, fielded during the 2000 presidential campaign. We model transitions in support for the major party candidates following the party conventions and presidential debates. In the aggregate, Gore support increases following the conventions (but not the debates), while Bush support increases with the debates (but not the conventions). But there is considerable microlevel variation in the data: responsiveness to campaign events is greatest among Independents, undecided voters, and "mismatched partisans," but exactly how these groups respond differs for each event. Moreover, attitudes toward then President Clinton mediate the effect of the campaign events on voter preferences. Two primary conclusions follow: (1) rich data sets are required to observe the effects of campaign events; (2) the influence of campaign events on vote choice is conditional on previous preferences, partisan dispositions, and political context. [source] | ||||||||||||||||