Gregory Duncan

We consider 3 questions regarding the effects of economic deprivation on child development. First, how are developmental outcomes in childhood affected by poverty and such poverty correlates as single parenthood, ethnicity, and maternal education? Second, what are the developmental consequences of the duration and timing of family economic deprivation? And, third, what is the comparative influence of economic deprivation at the family and neighborhood level? We investigate these issues with longitudinal data from the Infant Health and Development Program. We find that family income and poverty status are powerful correlates of the cognitive development and behavior of children, even after accounting for other differences--in particular family structure and maternal schooling--between low- and high-income families. While the duration of poverty matters, its timing in early childhood does not. Age-5 IQs are found to be higher in neighborhoods with greater concentrations of affluent neighbors, while the prevalence of low-income neighbors appears to increase the incidence of externalizing behavior problems.

OBJECTIVES: The aim of this study was to examine relationships between income and mortality, focusing on the predictive utility of single-year and multiyear measures of income, the shape of the income gradient in mortality, trends in this gradient over time, the impact of income change on mortality, and the joint effects of income and age, race, and sex on mortality risk. METHODS: Data were taken from the Panel Study of Income Dynamics for the years 1968 through 1989. Fourteen 10-year panels were constructed in which predictors were measured over the first 5 years and vital status over the subsequent 5 years. The panels were pooled and logistic regression was used in the analysis. RESULTS: Income level was a strong predictor of mortality, especially for persons under the age of 65 years. Persistent low income was particularly consequential for mortality. Income instability was also important among middle-income individuals. Single-year and multiyear income measures had comparable predictive power. All effects persisted after adjustment for education and initial health status. CONCLUSIONS: The issues of low income and income instability should be addressed in population health policy.

The comment by John Barron and Dan Black and the note by Duane Leigh (published December 1981, AER) are on the theoretical model and empirical evidence, respectively. We will respond to their comments in this order and offer new empirical evidence based on a panel component of the national Quality of Employment Survey of the Survey Research Center of the University of Michigan. The central point of the theoretical model is that given a world where there are unforeseen changes in the parameters facing a firm,' such as changes in prices or production technology, two conditions will necessitate some intragroup mechanisms, such as union procedures for grievances and reaching consensus, in order to realize efficiency. These two conditions are firm-specific attachment costs, such as search and training costs, and workplace public goods, such as the speed of the production process in assembly lines or the scheduling of workshifts.2 Firms differ in both attachment costs and extent of workplace public goods. At one extreme, suppose firm-specific attachment costs are so large that no workers can leave or come into the firm. Then in the presence of workplace public goods, the workers are faced with a traditional public finance problem of selecting the optimal level of the public good. At the other extreme, suppose there are no firm-specific attachment costs. Then we have the common assumption of a frictionless equilibrium in which workers move across firms and the public goods problem may be solved in the manner suggested by the Tiebout (1956) model: each worker selects his desired bundle of labor income and the shared working condition by choosing among firms. This process is consistent with the type of hedonic (labor) market equilibrium characterized by Sherwin Rosen (1974). From the point of view of an individual firm, efficiency in the intermediate case of some firm-specific attachment costs combined with shared working conditions or workplace public goods leads to a blend of market adjustments and the solution to a public goods problem for a less heterogeneous group of workers than in the pure public goods equilibrium. The comings and goings of workers can be thought of as one part of the process, and solving the public goods problem for those who are there after the comings and goings is another. In our formal model the role of attachment costs (in the form of a search cost, c) is highlighted. Our approach to modelling working conditions and unions is consistent with recent empirical work, including the observation that unionized workers have lower quit rates and thereby can have greater firm-specific human capital as indicated by higher productivity (Charles Brown and James Medoff, 1978). However, our approach adds the additional prediction that unions will be more likely to be present in certain work settings; specifically those with shared working conditions. Our approach therefore differs somewhat from that proposed by Richard Freeman (1980) since he does not emphasize the role of shared working conditions in encouraging unionism. *University of Michigan. 'More precisely, a workgroup. Some working conditions are firm-wide but many apply at the level of the workgroup or production site. 2An interesting historical example of workshift scheduling is the transition from two twelve-hour shifts to three eight-hour shifts in the steel industry. For some of the inherited workers an eight-hour day was not long enough (at the old wage rate), and even if none of the inherited workers quit, the firms needed 50 percent more workers. The transition was characterized by acrimony and bloodshed (William Hogan, 1971).

Despite considerable evidence documenting a strong and persistent relationship between socioeconomic position and mortality, recent research suggests that this association may be weaker among women. In our examination of gender differences in the socioeconomic gradient in mortality, we argue that this inconsistency arises from the failure to consider the ways in which gender is a fundamental constituent of socioeconomic position. The data used are from the Panel Study of Income Dynamics. Respondents, including all household heads and their partners, aged 29 years and older in 1972 (N = 5,665; 56% female), were followed until 1991, death, or attrition. Discrete time event history analysis was used to examine the predictors of death between 1972 and 1991. Of the key socioeconomic predictors, years of education was measured at baseline, while earned income was a time-varying covariate. We find no gender differences in the effect of respondents' own socioeconomic positions on their mortality risk. However, increasing spousal income raises men's odds of dying, while the opposite is true for women. Our results raise questions about the prevailing view that the socioeconomic gradient in mortality is weaker among women. Moreover, gender differences in the effects of spousal earnings on mortality risk suggest that their labor market rewards have fundamentally different meanings for women and men.

Echinococcus is a genus of tapeworm endemic in certain parts of the world but found only rarely in the United States. An extremely unusual case of an intramuscular infestation involving an extremity occurred in a 41-year-old man. Since the infestation closely resembled a soft-tissue tumor on clinical and roentgenographic examination, the patient was treated with an incisional biopsy of the mass, which consisted of a cystic cavity filled with clear fluid. The diagnosis of an Echinococcus cyst was made only after permanent section analysis revealed numerous scoleces within the cyst lining. The patient was asymptomatic six months after cyst excision but still remains at risk for recurrence of the infestation. The present report serves to alert the reader to this rare but potentially fatal condition. Preoperative diagnosis is imperative to avoid inadvertant rupture of a hydatid cyst, which releases viable scoleces into the systemic circulation and may precipitate an anaphylactic reaction.