Pipage Rounding: A New Method of Constructing Algorithms with Proven Performance Guarantee

The paper presents a general method of designing constant-factor approximation algorithms for some discrete optimization problems with assignment-type constraints. The core of the method is a simple deterministic procedure of rounding of linear relaxations (referred to as pipage rounding). With the help of the method we design approximation algorithms with better performance guarantees for some well-known problems including MAXIMUM COVERAGE, MAX CUT with given sizes of parts and some of their generalizations.     

Residential Mobility and Adolescent Achievement and Behavior: Understanding Timing and Extent of Mobility

Residential mobility is generally viewed as an adverse event for adolescents' development. Less is known about whether moving during adolescence, childhood, or both periods explains this connection and whether the extent of mobility matters. Analytic shortcomings with much of the research call into question extant findings. We examined associations between childhood, adolescent, and child–adolescent mobility and adolescents' achievement (math and reading) and behavior problems (internalizing and externalizing). With a multisite, longitudinal sample (N = 1,056), we employed propensity score methods, which mitigate concerns about selection bias on observed variables, to investigate relationships. Results suggest that multiple, child–adolescent movers had more internalizing problems in adolescence than their stable peers, but did not differ on externalizing problems or achievement.     

The influence of religiosity on charitable behavior: A COPPS investigation

We examine the role of religion in charitable giving and find that the religious preference of both the donor and the recipient organization influence giving behavior. By exploiting a panel survey of charitable giving, we demonstrate that traditional empirical analysis on charitable giving masks important differences among donor groups. Religious giving by religious individuals is least responsive to changes in price and income, while secular giving by secular individuals has the greatest sensitivity.     

Long-term care in Spain: Difficulties in professionalizing services

The aim of this article is to analyze the difficulties in professionalizing the long-term care system in Spain. Since 2006, the new Spanish law has recognized care as a subjective right, and regulations are being designed to create a framework for its professionalization. Nowadays, family remains the most important group of providers who care for their elders, and women remain the main informal caregivers. Why do families resist using public long-term care services and professional carers included in the new law? The hypothesis highlights sociocultural factors as an obstacle to professionalization of long-term care services in addition to political and economic factors. The results show qualitative data about expectations, preferences, and discourses that women caregivers have in relation to their responsibility. The empirical material includes 25 interviews with different profiles of caregivers and six focus groups with family caregivers. The article suggests that the Spanish ideal of care is a problem for the professionalization of services because the family remains as the main provider of care—without specific skills, knowledge, and abilities.     

Coalition-building and the forging of solidarity across difference and inequality

Diverse coalitions hold great potential for social movements, but they also face tremendous challenges. In this article, I review the literature on diverse alliances with a focus on how trust, commitment, and ultimately, solidarity can be developed and sustained across divides. The article begins by discussing the needs of diverse alliances to build trust and commitment, and the coalitional characteristics deemed vital for doing so, with a focus on shared neutral space, ongoing interaction, and social ties and bridgebuilders. Five coalitional processes and practices are identified and discussed that have been empirically found or theorized to be imperative for cultivating solidarity across difference and inequality. These processes include (a) uniting around shared principles while engaging difference; (b) acknowledging and managing inequalities; (c) making space for each other; (d) attention to managing conflicts; and (e) actions that confirm the shared commitments and negotiated identity. I conclude by evaluating the state of research on developing and sustaining alliances across divides.     

An omnibus lack of fit test in logistic regression with sparse data

The usefulness of logistic regression depends to a great extent on the correct specification of the relation between a binary response and characteristics of the unit on which the response is recoded. Currently used methods for testing for misspecification (lack of fit) of a proposed logistic regression model do not perform well when a data set contains almost as many distinct covariate vectors as experimental units, a condition referred to as sparsity. A new algorithm for grouping sparse data to create pseudo replicates and using them to test for lack of fit is developed. A simulation study illustrates settings in which the new test is superior to existing ones. Analysis of a dataset consisting of the ages of menarche of Warsaw girls is also used to compare the new and existing lack of fit tests.     

Long memory estimation for complex-valued time series

Statistics and Computing - Long memory has been observed for time series across a multitude of fields, and the accurate estimation of such dependence, for example via the Hurst exponent, is crucial...     

Myths about Russia

This article provides an interdisciplinary theoretical analysis of contemporary social mythology and summarizes the results of an empirical study. The main groups of mythologized images of Russia in the consciousness of modern youth include: mythologized images of Russian domain and the historical perspective of Russia; symbolic and metaphorical images of Russia; and the types of social world views that young people have. The aspects of the constructive and destructive impacts of myths about Russia described in this article may be used to analyze and interpret individual and group images of Russia among young people and to develop recommendations for preventing the destructive impact of the mythologization of Russia's image on the social processes and consciousness of modern youth.     

Postdisaster Housing Stages: A Markov Chain Approach to Model Sequences and Duration Based on Social Vulnerability

Housing recovery is an unequal and complex process presumed to occur in four stages: emergency shelter, temporary shelter, temporary housing, and permanent housing. This work questions the four-stage typology and examines how different types of shelter align with multiple housing recovery stages given different levels of social vulnerability. This article also presents a Markov chain model of the postdisaster housing recovery process that focuses on the experience of the household. The model predicts the sequence and timing of a household going through housing recovery, capturing households that end in either permanent housing or a fifth possible stage of failure. The probability of a household transitioning through the stages is computed using a transition probability matrix (TPM). The TPM is assembled using proposed transition probability models that vary with the social vulnerability of the household. Monte Carlo techniques are applied to demonstrate the range of sequences and timing that households experience going through the housing recovery process. A set of computational rules are established for sending a household to the fifth stage, representing a household languishing in unstable housing. This predictive model is exemplified on a virtual community, Centerville, where following a severe earthquake scenario, differences in housing recovery times exceed four years. The Centerville analysis results in nearly 5% of households languishing in unstable housing, thereby failing to reach housing recovery. These findings highlight the disparate trajectories experienced by households with different levels of social vulnerability. Recommendations are provided at the end for more equitable postdisaster recovery policies.