Maternal Functioning, Time, and Money: The World of Work and Welfare

Numerous studies have assessed families' employment and financial stability following welfare reform. Yet little research has addressed whether welfare and work transitions are linked with other changes in family functioning. Using a representative sample of approximately 2,000 low-income urban families from the Three-City Study, analyses assessed whether mothers' welfare and employment experiences over a two-year period following welfare reform were related to changes in family well-being. Lagged regression models controlling for family characteristics and earlier levels of functioning found that moving into employment and stable employment (of 30 hours or more per week) were linked to substantial increases in income and improvements in mothers' psychological well-being. Movements into employment also were associated with declines in financial strain and food insecurity. Sustained or initiated welfare receipt was related to relative declines in income, physical health, and psychological well-being, but also to improved access to medical care. In contrast, mothers' welfare and work experiences showed very limited relations to changes in the quality of parenting or of children's home environments. These patterns were similar for families with young children and those with adolescent children. Results suggest that parenting behaviors are more resistant to change than are maternal emotional and economic functioning.     

Maternal Welfare and Employment Experiences and Adolescent Well-Being: Do Mothers' Human Capital Characteristics Matter?

Using a representative sample of over 900 low-income urban families from the Three-City Study, analyses assessed whether maternal human capital characteristics moderate relationships between mothers' welfare and employment experiences and young adolescents' well-being. Results indicate synergistic effects whereby greater maternal education and literacy skills enhanced positive links between mothers' new or sustained employment and improvements in adolescent cognitive and psychosocial functioning. Greater human capital also enhanced the negative links between loss of maternal employment and adolescent functioning. Mothers' entrances onto welfare appeared protective for adolescents of mothers with little education but predicted decreased psychosocial functioning among teens of more educated mothers. Results suggest that maternal human capital characteristics may alter the payback of welfare and work experiences for low-income families.     

The interaction of aging and 10 years of racing on ultraendurance running performance

The aim of this study was to examine the interaction between aging and 10 years of racing in endurance runners. Race-time data from 194 runners who had completed 10 consecutive 56-km ultramarathons were obtained. The runners were either 20.5 +/- 0.7, 30.0 +/- 1.0, 39.9 +/- 0.9, or 49.4 +/- 1.0 years old at their first race. Each runner's race speed was determined for each race over the 10 years. Data were analyzed using repeated-measures ANOVA, one-way ANOVA, and independent t tests and showed that performance improved and declined at greater rates for younger runners; younger runners had a greater capacity for improvement than older runners; approximately 4 years were required to reach peak racing speed, regardless of age; it was not possible to compete at peak speed for more than a few years; and the combined effects of 10 years of aging and racing neither improve nor worsen net performance. In conclusion, these data suggest that although these runners showed similar patterns of change in race speed over a 10-year period, the extent of change in performance was greater in younger than in older runners.     

Decision and choice in transforming data

Statistics are developed for predicting the effect of data transformations on the F statistic when the assumptions of homoscedasticity and normality underlying the AN OVA are not necessarily satisfied. These statistics are useful for determining whether and how to transform, They are developed by partitioning the change in the observed value of the jF-statistic under the transformation, into two expressions, one of which depends on the "truth" of HQ while the other does not. Using this partition, desirable properties are derived for transformations. Criteria are developed defining transformations which tend to preserve the type 1 error while increasing power when needed. Using these criteria, the notion of model robustness is introduced. It is shown that the Box-Cox methodology for selecting a power transform may, under certain conditions, produce a transformation which does not permit inferences to be made about the parent population from the transformed population. An alternative approach suggested here does permit such inferences.     

Size,Skill and Sorting

Abstract. The rise in inequality between the 1970s and the 1990s and the persistent gap in pay between large and small employers are two of the most robust findings in the study of labor markets. Mainstream economists focus on differences in observable and unobservable skills to explain both the overall rising inequality and the size–wage gap. In this paper we model how increasing returns to skill can affect the size–wage gap both with constant sorting and with size‐biased, skill‐biased technological change (e.g. if large firms always had access to computers, but small firms gained access to computers with the rise of affordable personal computers). We analyze the Current Population Surveys from 1979 to 1993 to determine whether large and small employers are converging in terms of mean wages (the employer size–wage effect), wage structures by occupation and education, characteristics of employees, and wage structures by region. We find mixed evidence of convergence and no consistent support for any single version of human capital theory.     

Does Market Incompleteness Matter?

This paper argues that incompleteness of intertemporal financial markets has little effect (on welfare, prices, or consumption) in an economy with a single consumption good, provided that traders are long–lived and patient, a riskless bond is traded, shocks are transitory, and there is no aggregate risk. In an economy with aggregate risk, a similar conclusion holds, provided traders share the same CRRA utility function and the right assets are traded. Examples demonstrate that these conclusions need not hold if the wrong assets are traded or if the economy has multiple consumption goods.