Couple Relationship Status and Patterns in Early Parenting Practices

Using data from the Fragile Families and Child Wellbeing Study (N = 3,003), we examine the role of parental relationship status at birth on maternal adherence to current recommendations regarding breastfeeding, corporal punishment, and well‐child visits. At the bivariate level, parents’ union status is almost linearly related to adherence to recommendations. Multivariate models, however, reveal that much of the association stems from the selection of more advantaged individuals into more serious relationships. The results suggest that, although relationship status may be an accurate indicator of parents who are at risk of not adhering to recommended parenting behaviors, the underlying causes of nonadherence are more complex.     

A New Look at Quartiles of Ungrouped Data

Traditional methods of calculation of quartiles for ungrouped data are based on interpolation. In this article we focus on three methods of defining measures of this kind. Then we present hinges that divide data into four parts by a lower hinge, a median, and an upper hinge. A hinge is “crudely, a quartile.” The preceding four techniques may yield different numerical answers when applied to the same set of data. Two tests are proposed and are used to evaluate the various methods for calculation of quartiles and hinges. Finally, an alternative method of calculating quartiles is provided; it retains desirable characteristics of quartiles and combines them with the advantages ascribed to hinges.     

On step fixed-charge transportation problem

The fixed-charge problem is a nonlinear programming problem of practical interest in business and industry. One of its variations is the fixed-charge transportation problem (FCTP) where fixed cost is incurred for every route that is used in the solution, along with the variable cost that is proportional to the amount shipped. That cost structure causes the value of the objective function Z to also behave like a step function. Each time we open or close a route the objective function jumps a step. The step fixed-charge transportation problem (SFCTP) is a variation of the FCTP where the fixed cost is in the form of a step function dependent on the load in a given route. While the value of the objective function Z in the FCTP is a step function, the introduction of the step fixed cost in the SFCTP results in the objective function Z being itself a step function with many more steps. Fixed-charge problems are usually solved using sophisticated analytical or computer software. This paper discusses the theory of SFCTP and presents a computationally simple heuristic algorithm for solving small SFCTPs.     

Managed care liability.

Debate is heating up concerning proposals that patients have the right to sue their managed care plans for damages from wrongful denial of benefits or delays in care. Some states have recently passed legislation to address this issue and it is expected to be an area of intense legislative debate during this year. As managed care entities increasingly enter the realm of medical decision-making, the additional burden of this responsibility is taking shape. Whether managed care plans should be treated like providers of care and be held accountable for decisions that impact patient outcomes, or be viewed only as insurers is a policy question of immense proportion.     

The unconscious in economic decision-making: Convergent voices

Mainstream economics assumes that decision-making is a conscious cost-benefit process, ignoring the pervasive role of unconscious thought processes. Recent research in neuroimaging, genomics, and psychoanalysis exposes the role of unconscious and “nonconscious” processes, providing tools for analyzing economic decision-making. Neuroimaging reveals examples of brain function that modulate decision-making, but are not under conscious control. Psychoanalytic research provides evidence of the role of emotions and the unconscious in human behavior and decision-making. We advance the case for integrating psychoanalysis and neuroscience for a new perspective on the role of the mind in decision-making and economic behavior.     

Individual-level modeling of the spread of influenza within households

A class of individual-level models (ILMs) outlined by R. Deardon et al., [Inference for individual level models of infectious diseases in large populations, Statist. Sin. 20 (2010), pp. 239–261] can be used to model the spread of infectious diseases in discrete time. The key feature of these ILMs is that they take into account covariate information on susceptible and infectious individuals as well as shared covariate information such as geography or contact measures. Here, such ILMs are fitted in a Bayesian framework using Markov chain Monte Carlo techniques to data sets from two studies on influenza transmission within households in Hong Kong during 2008 to 2009 and 2009 to 2010. The focus of this paper is to estimate the effect of vaccination on infection risk and choose a model that best fits the infection data.     

Gradient boosting for distributional regression: faster tuning and improved variable selection via noncyclical updates

We present a new algorithm for boosting generalized additive models for location, scale and shape (GAMLSS) that allows to incorporate stability selection, an increasingly popular way to obtain stable sets of covariates while controlling the per-family error rate. The model is fitted repeatedly to subsampled data, and variables with high selection frequencies are extracted. To apply stability selection to boosted GAMLSS, we develop a new “noncyclical” fitting algorithm that incorporates an additional selection step of the best-fitting distribution parameter in each iteration. This new algorithm has the additional advantage that optimizing the tuning parameters of boosting is reduced from a multi-dimensional to a one-dimensional problem with vastly decreased complexity. The performance of the novel algorithm is evaluated in an extensive simulation study. We apply this new algorithm to a study to estimate abundance of common eider in Massachusetts, USA, featuring excess zeros, overdispersion, nonlinearity and spatiotemporal structures. Eider abundance is estimated via boosted GAMLSS, allowing both mean and overdispersion to be regressed on covariates. Stability selection is used to obtain a sparse set of stable predictors.     

¿Amigo de la Raza? Reexamining Determinants of Latino Support in the U.S. Congress*

Objectives. This study updates and extends research on substantive Latino representation in the U.S. Congress. An improved method of measuring “Latino interests” is proposed. Methods. Using a scorecard from the National Hispanic Leadership Agenda as the dependent variable, standard OLS regression is employed to determine the variables that best predict how members of the 108th Congress vote on issues that are salient to the Latino community. Results. The findings indicate that Latinos are substantively represented overwhelmingly by Democrats and those from majority‐Democratic districts or states, while religion and level of constituency poverty also play a notable role. Conclusion. This study adds strong support to the “party as a substantive representative” model of minority representation. It also shows that Latinos are not more likely to be substantively represented by fellow Latinos, nor do larger Latino constituencies affect a lawmaker's propensity to vote in favor of Latino interests.     

Why do richer democracies survive?—The non-effect of unconventional political participation

Since Seymour Lipset's (1959) seminal article on the social prerequisites of democracy, many scholars have found a strong empirical correlation between increases in per capita income and democracy. Given this strong connection however, an important gap in the literature remains—what are the pathways linking wealth and democracy? This paper attempts to establish the validity of one of the possible paths by testing the three-fold relationship between per capita Gross Domestic Product (GDP), unconventional political participation and democratic consolidation. Despite finding a strong positive correlation between per capita GDP and the consolidation of democracy, this research reveals that unconventional political participation is not mediating this effect.