A repeated observation approach for estimating the street homeless population

Risks of life on the street caused by inclement weather, harassment, and assault threaten the unsheltered homeless population. We address some challenges of enumerating the street homeless population by testing a novel capture-recapture (CR) estimation approach that models individuals' intermittent daytime visibility. We tested walking and vehicle-based variants of CR in downtown Toronto in March. Estimates that assume individual variability of sighting probabilities are most consistent with our knowledge of the homeless and achieve the most favorable confidence intervals, estimated detection probabilities, and coefficient of variation. Estimation bias from interobserver discrepancies, duplicate counting, and violation of the closed population assumption were minimized with uniform identification criteria, training, and sampling design. Bias caused by the social grouping of the homeless was small. Despite the limitations of visual identification, CR approaches as part of a multiple-method program can aid community responses to immediate needs on the street, especially during the harsh winter months.     

Beyond Guilt and Stigma: Changing Attitudes among Israeli Migrants in Canada

Over 60 years ago, the Jewish nationalist movement known as Zionism culminated in the creation of the State of Israel. Millions of Jews immigrated to Israel over the twentieth century, a process known as aliya (literally, “going up”). Yet over the years, thousands of Israelis have also chosen to leave Israel in a movement termed yerida (“going down”). As the term suggests, this reverse migration has been highly stigmatized. During the 1960s and 1970s, emigrants were publicly disparaged in the Israeli media for having abandoned a struggling state. Consequently, Israeli migrants suffered strong feelings of guilt that often, hampered their integration process abroad, a phenomenon observed as late as the 1990s. This paper, however, reveals that feelings of stigmatization have greatly decreased among Israeli migrants in recent years. The study is based on research that I conducted in 2008–2009, involving nine months of participant observation in Vancouver’s Israeli community and 34 in‐depth interviews. Unlike in previous studies, most of my informants expressed no feelings of guilt over having left Israel. Of those who did, most framed their guilt as a longing for family and friends rather than the patriotic longing for the land as expressed by previous generations. Previous studies have also found that Israelis harbour a “myth of return”– a continuously expressed desire to return to Israel and a reluctance to accept their stay abroad as permanent. However, I have not found that the myth of return is still strong today, despite the continued prevalence of a strong sense of Israeli identity among Israelis abroad. I suggest that these changing attitudes are the product of shifting ideals in Israeli society that have developed as the state of Israel has matured. This paper thus serves to update the outdated image of Israeli migrants as it exists in the prevailing literature.     

The Validity of the Day Reconstruction Method in the German Socio-economic Panel Study

The Day Reconstruction Method (DRM) is a useful tool for evaluating short-term changes in emotional experiences over a variety of daily situations. However, traditional method of collecting DRM data can be time-intensive for both researchers and participants. In this paper we provide evidence that a random-sampling approach to DRM assessment can provide useful data that are largely consistent with previous research that used the full version of the DRM. In a nationally representative sample of 2303 people, we demonstrate that (1) there is variability in emotional ratings of episodes that replicates what has been found in prior studies, (2) correlations with global measures are typically small in magnitude (<0.30), (3) correlations with personality are for the most part negligible, (4) correlations with global ratings of domain satisfaction are higher for domain-relevant situations, and (5) parents report more positive affect while providing care for their children when compared to other activities, and this effect can account for the observed differences in emotional experiences of parents and non-parents.     

DOES THE WOMEN,INFANTS, AND CHILDREN PROGRAM IMPROVE INFANT HEALTH OUTCOMES?

We reevaluate the causal impacts of prenatal participation in the Women, Infants, and Children (WIC) supplemental nutrition program on birth outcomes by simultaneously accounting for self-selection into WIC and systematic underreporting of program participation. Combining survey data from the Early Childhood Longitudinal Study-Birth Cohort with administrative data from the USDA, we extend partial identification methods to reflect institutional details of the WIC program and validate WIC program participation for a mixture of positive and negative responses. Our preferred estimates imply that WIC increases the prevalence of normal birth weight by at least 4.8% and normal gestation duration by at least 3.7%. (JEL C14, C21, I12, I31, I38)     

Technological newness: An empirical study in the process industries

Technological change in product development is a crucial issue in the management of technology. The entire sweep of technological changes over the past hundred of years is, in essence, the sum of thousands of individual product development projects in thousands of firms. Yet the degree of technological change in individual development projects has not been extensively studied. This paper presents a four-dimensional characterization of technological newness for product development projects in the process industries in which product development is closely tied to process innovation. The characterization uses four dimensions of change that are required in the development of new products: chemistry, production equipment, fabrication technology and process control. Based on the framework of technological newness, the paper presents data collected on the degree of process change in a set of 20 product development projects conducted by a large manufacturer of advanced polymers. The data provide a clear demonstration of the value of the measurement framework, showing a strong relationship between the characterization of change and the project performance.     

Motivation factors for participation in GLBT sports league

This study investigated those factors that motivate members of the GLBT (gay, lesbian, bisexual, transgender) community to participate in a GLBT sports league. Data from a survey of 1151 members of a Chicago GLBT sports association were analyzed using exploratory factor analysis to determine the variables that contributed most to explaining leisure motivation in this setting. Results showed that the intellectual and social factors were the primary factors in determining motivation in participation. Also contributing to determining motivation were competency mastery and stimulus avoidance. In addition, findings suggested there was no primary difference between male and female participants.     

STRUCTURING THE LEISURE MARKET—A MULTIVARIATE ANALYSIS

The derivation of an empirically based classification scheme for the leisure market is discussed from both a substantive and methodological viewpoint. The substantive findings relate to the manner in which respondents structured relationships among 12 leisure activities and to the criteria they used in doing so. Based on the apparent structure, a number of activity types were identified. The methodological thrust of the article provides one example of how a variety of multivariate methods (multidimensional scaling, property fitting, cluster analysis and factor analysis) can be employed to form a system of complementary techniques aimed at providing an in-depth understanding of data and the phenomena they describe.     

Testing for center effects on survival and competing risks outcomes using pseudo-value regression

In multi-center studies, the presence of a cluster effect leads to correlation among outcomes within a center and requires different techniques to handle such correlation. Testing for a cluster effect can serve as a pre-screening step to help guide the researcher towards the appropriate analysis. With time to event data, score tests have been proposed which test for the presence of a center effect on the hazard function. However, sometimes researchers are interested in directly modeling other quantities such as survival probabilities or cumulative incidence at a fixed time. We propose a test for the presence of a center effect acting directly on the quantity of interest using pseudo-value regression, and derive the asymptotic properties of our proposed test statistic. We examine the performance of our proposed test through simulation studies in both survival and competing risks settings. The proposed test may be more powerful than tests based on the hazard function in settings where the center effect is time-varying. We illustrate the test using a multicenter registry study of survival and competing risks outcomes after hematopoietic cell transplantation.

     

Statistical methods to evaluate health effects associated with major sources of air pollution: a case-study of breathing patterns during exposure to concentrated Boston air particles

Summary.  We conduct a case-study evaluating the source-specific effects of particulate matter on respiratory function. Using a structural equation approach, we assess the effect of different receptor models on the estimated source-specific effects for univariate respiratory response. Furthermore, we extend the structural equation model by placing a factor analysis model on the response to represent the measured respiratory responses in terms of underlying respiratory patterns. We estimate the particulate matter source-specific effects on respiratory rate, accentuated normal breathing and airway irritation and find a strong increase in airway irritation that is associated with exposure to motor vehicle particulate matter.     

Gender,Race, and Perceived Environmental Risk: The “White Male” Effect in Cancer Alley,LA

Research on risk perceptions are replete with race- and gender-specific hypotheses attempting to account for attitudinal variation. However, race and gender differences may mask more notable patterns across subgroups, patterns that lie at the intersection of race and gender. Recent national studies suggest that being a White male leads to lower risk perceptions and greater willingness to accept risks. This article extends this research by examining the “White male” effect in a chronically polluted context, an area where industrial pollution is palpable and well-documented. Data are drawn from a survey of a population living in “Cancer Alley,” a stretch of the Mississippi River from Baton Rouge to New Orleans. We find that women more than men and Blacks more than Whites perceive environmental risks as serious. Further, evidence suggests that these differences are mostly due to the relatively extreme perceptions of risk accepting White males and risk adverse Black females. After controlling for select variables in hierarchical multiple regression analyses, being a White male or Black female still has a statistically significant impact on risk perceptions.