The ecology of social networks in four urban neighborhoods

This paper re-examines the question of the social “fabric” of urban neighborhoods on the basis of residents' personal networks. Data were collected on the number, relative intimacy, and spatial distribution of social relationships among residents of two ethnically homogenous and two ethnically heterogenous neighborhoods in a medium-sized city in the midwestern United States. The analysis focused on spatial distributions and variables associated with differences in the average number or intimacy of neighborhood network ties. Herbert Gans had predicted that in heterogenous neighborhoods residential proximity would be a less important factor in social network formation than has previously been reported for socially homogeneous residential settings (especially Festinger et al. 1950). The results from this study indicated that the effects of proximity were more, rather than less, reflected in the spatial distribution of social relationships in the ethnically heterogenous neighborhoods. The face-block was identified as an important socio-spatial unit in all four neighborhoods.     

The efficacy of early intervention programs for children with organic impairment: A quantitative review

The results of studies examining the effectiveness of early intervention for infants and children with organic impairment and developmental delay were reviewed using recently developed quantitative methods that treat the literature review process as a unique type of scientific inquiry. Thirty-eight studies meeting certain predetermined criteria were included in the review. The 38 studies contained a total of 118 statistical hypothesis tests that evaluated the effectiveness of early intervention. An analysis of these tests based on the calculation of effect sizes revealed that subjects receiving early intervention performed better on a wide range of dependent measures than subjects not receiving intervention. The outcomes were found to be related to several design and study characteristics. Larger effect sizes were associated with preexperimental designs, and also with studies in which the internal validity was rated as poor. Several other design variables such as how subjects were assigned to conditions and how the dependent measure was recorded were related to study outcome as measured by effect size. The conclusion was made that an accurate interpretation of the early intervention research literature cannot be made without consideration of specific design variables and study characteristics.     

Penalized likelihood regression: General formulation and efficient approximation

The authors consider a formulation of penalized likelihood regression that is sufficiently general to cover canonical and noncanonical links for exponential families as well as accelerated life models with censored survival data. They present an asymptotic analysis of convergence rates to justify a simple approach to the lower‐dimensional approximation of the estimates. Such an approximation allows for much faster numerical calculation, paving the way to the development of algorithms that scale well with large data sets.     

Religion and Giving in Australia

This article draws on a household survey of giving and volunteering undertaken as part of the Giving Australia project to explore the relationship between religion and the giving behaviour of adult Australians. We find that people who identify themselves as having a religion are more likely to give and to give more on average than people who do not but that this relationship is produced by a subset of this group; namely, people who regularly attend religious services. Indeed, the likelihood of giving and average amounts given by givers over a year increase with levels of attendance at religious services. The relationship holds even after allowing for other factors that affect the likelihood of a person giving and the amount given. It also holds for giving to nonreligious causes (ie when giving to religion is omitted). However, when we also omit giving to charities and look at giving to civic causes alone we find that the frequency of attendance at religious services has an ambiguous relationship with giving. A suggestion in overseas literature that it is participation in religious groups, rather than attendance at religious services that is associated with giving is not supported.     

Highways and Population Change*

Abstract In this paper we return to an issue often discussed in the literature regarding the relationship between highway expansion and population change. Typically it simply is assumed that this relationship is well established and understood. We argue, following a thorough review of the relevant literature, that the notion that highway expansion leads to increased population growth in the vicinity of the improved infrastructure finds only weak and often conflicting support. Using data on all major highway expansions in Wisconsin covering the period from the late‐1960s through the 1990s from the Wisconsin Department of Transportation (WisDOT), and census data at the minor civil division (MCD) level covering the period 1970 to 2000, we deploy the analytical tools of geographic information system (GIS) software, and theory from the expanding literature in spatial analysis and modeling, to take a fresh look at this relationship. Our analysis reveals that there is a modest relationship between highway expansion and population growth among MCDs within 10–20 miles of the expanded major highway. The causal structure, however, is complex. Our starting hypothesis argues that population growth precedes highway expansion as frequently as population growth results from highway expansion, but the data show otherwise. The dominant causal influence appears to flow from highway expansion to population growth.     

Interval estimation for log-linear models with one variable subject to non-ignorable non-response

Summary.  Log-linear models for multiway contingency tables where one variable is subject to non-ignorable non-response will often yield boundary solutions, with the probability of non-respondents being classified in some cells of the table estimated as 0. The paper considers the effect of this non-standard behaviour on two methods of interval estimation based on the distribution of the maximum likelihood estimator. The first method relies on the estimator being approximately normally distributed with variance equal to the inverse of the information matrix. It is shown that the information matrix is singular for boundary solutions, but intervals can be calculated after a simple transformation. For the second method, based on the bootstrap, asymptotic results suggest that the coverage properties may be poor for boundary solutions. Both methods are compared with profile likelihood intervals in a simulation study based on data from the British General Election Panel Study. The results of this study indicate that all three methods perform poorly for a parameter of the non-response model, whereas they all perform well for a parameter of the margin model, irrespective of whether or not there is a boundary solution.     

A comparison study of realtime fatality rates: severe acute respiratory syndrome in Hong Kong, Singapore, Taiwan, Toronto and Beijing, China

Summary.  In an outbreak of a completely new infectious disease like severe acute respiratory syndrome (SARS), estimation of the fatality rate over the course of the epidemic is of clinical and epidemiological importance. In contrast with the constant case fatality rate, a new measure, termed the 'realtime' fatality rate, is proposed for monitoring the new emerging epidemic at a population level. A competing risk model implemented via a counting process is used to estimate the realtime fatality rate in an epidemic of SARS. It can capture and reflect the time-varying nature of the fatality rate over the course of the outbreak in a timely and accurate manner. More importantly, it can provide information on the efficacy of a certain treatment and management policy for the disease. The method has been applied to the SARS data from the regions affected, namely Hong Kong, Singapore, Toronto, Taiwan and Beijing. The magnitudes and patterns of the estimated fatalities are virtually the same except in Beijing, which has a lower rate. It is speculated that the effect is linked to the different treatment protocols that were used. The standard estimate of the case fatality rate that was used by the World Health Organization has been shown to be unable to provide useful information to monitor the time-varying fatalities that are caused by the epidemic.