The Changing Demography of America's Families

We use data from a variety of sources to describe recent dramatic changes in the composition, economic stability, and diversity of American families. The declining prevalence of early marriage, increasing level of marital dissolution, and growing tendency to never marry, especially among some racial and ethnic groups, reflect changes in the relative economic prospects of men and women and support the conclusion that marriage is becoming less valued as a source of economic stability. These developments also imply that relatively more children are born outside of marriage, spend at least part of their childhood in a single‐parent household, and endure multiple changes in family composition. Paralleling these trends have been sharp changes in the economic stability of families, characterized most notably by a growing importance of women's income and increasing economic inequality among American families.     

Ambulance allocation for maximal survival with heterogeneous outcome measures

This paper proposes new models for locating emergency medical services (EMS) by incorporating survival functions for capturing multiple-classes of heterogeneous patients. The Maximal Expected Survival Location Model for Heterogeneous Patients (MESLMHP) aims to maximize the overall expected survival probability of multiple-classes of patients, whereby different classes could be defined according to agreed patient categories based on response time targets, or by capturing differing medical conditions each with a corresponding survival function. Furthermore, we propose and demonstrate an approximation approach to solving the extended stochastic version of MESLMHP, which utilizes queuing theory to permit the modeling of congestion and utilization at each ambulance station, and does not require assumptions to be made on the utilization of ambulances. Both models are demonstrated using data from the ambulance service in Wales. We show that our multiple outcome measures and survival-maximizing approach, rather than one based on average response time targets alone or a single patient class provides more effective EMS ambulance allocations.     

The Gamma Distribution as a Mixture of Exponential Distributions

A gamma distribution with arbitrary scale parameter θ and shape parameter r < 1 can be represented as a scale mixture of exponential distributions.     

Bias in transition-specific survival and movement probabilities estimated using capture-recapture data

Transition probabilities can be estimated when capture-recapture data are available from each stratum on every capture occasion using a conditional likelihood approach with the Arnason-Schwarz model. To decompose the fundamental transition probabilities into derived parameters, all movement probabilities must sum to 1 and all individuals in stratum r at time i must have the same probability of survival regardless of which stratum the individual is in at time i + 1. If movement occurs among strata at the end of a sampling interval, survival rates of individuals from the same stratum are likely to be equal. However, if movement occurs between sampling periods and survival rates of individuals from the same stratum are not the same, estimates of stratum survival can be confounded with estimates of movement causing both estimates to be biased. Monte Carlo simulations were made of a three-sample model for a population with two strata using SURVIV. When differences were created in transition-specific survival rates for survival rates from the same stratum, relative bias was <2% in estimates of stratum survival and capture rates but relative bias in movement rates was much higher and varied. The magnitude of the relative bias in the movement estimate depended on the relative difference between the transition-specific survival rates and the corresponding stratum survival rate. The direction of the bias in movement rate estimates was opposite to the direction of this difference. Increases in relative bias due to increasing heterogeneity in probabilities of survival, movement and capture were small except when survival and capture probabilities were positively correlated within individuals.     

Counseling for Continued Career Development After Retirement: An Application of the Theory of Work Adjustment

The theory of work adjustment (TWA; R. V. Dawis & L. H. Lofquist, 1984; L. H. Lofquist & R. V. Dawis, 1969, 1991) is useful in addressing the career counseling needs of retirees who want to continue working but who need to explore their career choices before settling on a new occupation or job. This article examines some of the challenges that midlife and older adults face as they plan postretirement careers. Information about TWA and a case example are provided to assist counselors in understanding how TWA can be applied to retirement career counseling.     

Visualizing Structure: Reading Surfaces of Social Life

This paper reports on the use of aerial photographs to study the social structure of a dairy farm neighborhood in St. Lawrence County, New York. The paper compares information from aerial photographs of farmsteads and farm work to data gathered in a sociological survey. I examine how the visual data compares to other sociological information; how photographs, in this research, amplify, supplement, or contextualize nonvisual data.     

Economic conditions,marital status,and the timing of first births: Results for whites and blacks

Relatively little is known about the effects of aggregate economic conditions on first-birth timing. In this paper, we argue that aggregate economic conditions are important macrolevel forces driving the transition to parenthood. We develop and test a causal model, separately by race, in which economic conditions influence both marital status and first-birth timing. Our results indicate that economic conditions are significant predictors of both outcomes, with economic conditions for females having effects different from those for males. A particularly noteworthy finding is that favorable wage trajectories for females lead to a decreased likelihood of being married and slower birth timing (a finding opposite to that predicted on the basis of opportunity costs). For blacks, the majority of the effects of economic conditions on the transition to parenthood are direct, while for whites a significant proportion of effects are indirect through marital status.     

DIRECT AND INDIRECT EFFECTS OF RELIGION ON BIRTH TIMING:

The effect of being Catholic on first-birth timing (hereafter, birth timing) varies according to how the dependent variable is measured. When birth timing is measured as age at first birth, Catholics' is slower than non-Catholics'; measured as duration from marriage, Catholics' is more rapid. Structural equation models for discrete data showing these findings explain that Catholics marry later than non-Catholics. The direct effect of being Catholic is to speed birth timing, while the larger, indirect effect (through marital status) is to slow it.