Bayesian credible intervals for response surface optima

In response surface methodology, one is usually interested in estimating the optimal conditions based on a small number of experimental runs which are designed to optimally sample the experimental space. Typically, regression models are constructed from the experimental data and interrogated in order to provide a point estimate of the independent variable settings predicted to optimize the response. Unfortunately, these point estimates are rarely accompanied with uncertainty intervals. Though classical frequentist confidence intervals can be constructed for unconstrained quadratic models, higher order, constrained or nonlinear models are often encountered in practice. Existing techniques for constructing uncertainty estimates in such situations have not been implemented widely, due in part to the need to set adjustable parameters or because of limited or difficult applicability to constrained or nonlinear problems. To address these limitations a Bayesian method of determining credible intervals for response surface optima was developed. The approach shows good coverage probabilities on two test problems, is straightforward to implement and is readily applicable to the kind of constrained and/or nonlinear problems that frequently appear in practice.     

THE USE OF AGGREGATE DATA TO ESTIMATE GOMPERTZ‐TYPE OLD‐AGE MORTALITY IN HETEROGENEOUS POPULATIONS

We consider two related aspects of the study of old‐age mortality. One is the estimation of a parameterized hazard function from grouped data, and the other is its possible deceleration at extreme old age owing to heterogeneity described by a mixture of distinct sub‐populations. The first is treated by half of a logistic transform, which is known to be free of discretization bias at older ages, and also preserves the increasing slope of the log hazard in the Gompertz case. It is assumed that data are available in the form published by official statistical agencies, that is, as aggregated frequencies in discrete time. Local polynomial modelling and weighted least squares are applied to cause‐of‐death mortality counts. The second, related, problem is to discover what conditions are necessary for population mortality to exhibit deceleration for a mixture of Gompertz sub‐populations. The general problem remains open but, in the case of three groups, we demonstrate that heterogeneity may be such that it is possible for a population to show decelerating mortality and then return to a Gompertz‐like increase at a later age. This implies that there are situations, depending on the extent of heterogeneity, in which there is at least one age interval in which the hazard function decreases before increasing again.     

Public Sociology on Twitter: a Space for Public Pedagogy?

Research has examined various elements of Twitter; however, no scholarship has explored how sociologists currently use the platform. This empirically driven paper explores how individuals that self-identify as sociologists on Twitter use the popular micro-blogging social media site. A total of 152,977 tweets from Twitter profiles of 130 sociologists were collected and examined using qualitative media analysis. The potential use of Twitter allows the sociologist to become both the generator and interlocutor of dialogue with publics. We frame our data analysis and discussion around the core theme of expertise - namely, the role that expertise plays in the use of Twitter by sociologists. Our findings indicate that when sociologists used Twitter as sociologists (i.e., drawing upon their stated research expertise) little direct engagement with publics occurred. Thus, while sociologists appear to be using Twitter as a space for public sociology, the use of this interactive platform is mostly limited to the generation of content, a finding consistent with Burawoy’s traditional form of public sociology. Suggestions for future research are noted.     

Becoming a Race-Conscious Social Studies Teacher: The Influence of Personal and Professional Experiences

In this interpretive case study the researchers examined the beliefs of 13 self-identifying race-conscious secondary social studies teachers from diverse racial or ethnic, gender, and school-context backgrounds. The researchers found that the teachers' beliefs and views of practice were generally aligned with the main assertions of critical race theory. The teachers described their personal and professional experiences as a major influence on their race-conscious beliefs and views of practice. Moreover, teachers in diverse contexts described having to learn how to navigate the different racial experiences of the students in their classrooms, while teachers in racially segregated contexts (predominately White, Black, or Latino) emphasized the importance of teaching their students about others. Finally, despite the teachers' regular integration of race-related issues into their required and elective courses, they expressed a desire to have more opportunities to teach about race.     

REPEATED LOBBYING BY COMMERCIAL LOBBYISTS AND SPECIAL INTERESTS

Developing a lobbying model of repeated agency, we explain previously unexplained features of the real‐world lobbying industry. Lobbying is divided between direct representation by special interests to policymakers, and indirect representation where special interests employ professional intermediaries called commercial lobbyists to lobby policymakers on their behalf. Our analytical structure allows us to explain several trends in lobbying. For example, using the observation that in the United States over the last 20 years, policymakers have spent an increasing amount of their time fundraising as opposed to legislating, we are able to explain why the share of commercial lobbyist activity in total lobbying has risen dramatically and now constitutes over 60% of the total. The key scarce resource in our analysis is policymakers' time. Policymakers allocate this resource via implicit repeated agency contracts that are used to incent special interests and commercial lobbyists to provide a mix of financial contributions and information on policy proposals. These implicit agency contracts solve both an information problem in the presence of unverifiable policy information and a contracting problem in the absence of legal enforcement. These repeated relationships, that are often described using the pejorative term “cronyism” in the popular press, may in certain circumstances be welfare improving. (JEL D72, D82, H1, P16)     

Emerging issues in urban ecology: implications for research,social justice,human health,and well-being

Urbanization affects landscape structure and the overall human condition in numerous ways. Green spaces include vegetated land cover (e.g., urban forests, trees, riparian zones, parks) which play a distinctive role in urban ecology. This article reviews emergent literature on the linkages between urban green spaces, social justice, and human health. We explore this subject in the context of landscape structure, ecosystem services, and distributional equity as it relates to various health outcomes. Finally, we conclude by identifying gaps in the scholarship and potential areas of future research.     

Beyond Petliura: the Ukrainian national movement and the 1919 pogroms

On the basis of largely unused archival materials in Kyiv, this article re-examines the responsibility of the Ukrainian People’s Republic (UNR) for the pogroms of 1919. It consciously puts aside the question of Symon Petliura’s personal guilt, preferring to concentrate on the broader responsibility of members of the Ukrainian national movement for propagating antisemitic stereotypes and engaging in anti-Jewish violence. This approach reveals a widely held belief among members of the UNR that they were fighting a Jewish Bolshevik enemy. This led to pogroms but also probably prevented the UNR from punishing its soldiers who had perpetrated them. Despite the declarations by UNR figures condemning pogroms and the creation of an organ to investigate them, there were apparently very few, if any, convictions, at least in 1919, the year of the worst pogroms.     

Mental illness etiology beliefs among African American men with serious mental illness and their social support networks

Semi-structured qualitative interviews were conducted with 26 African American men with serious mental illness who were consumers of community mental health services and 26 members of their social support networks. All participants were asked what they believed had caused the consumers’ mental illness. Consumer participants most commonly identified chronic life stressors as a causal factor, while social supports most often identified intrinsic factors such as genetics or biology as causes of mental illness. Some support participants believed that unintentional drug use had precipitated the onset of mental illness or had no causal theories. The fact that some support participants could not identify a causal explanation may indicate failure on the part of mental health care systems to engage with consumers’ social support networks and provide education about mental illness and its causes. The implications of etiology beliefs on mental health service utilization are discussed.