The effects of motherhood timing on career path

This paper estimates the effects of motherhood timing on female career path, using biological fertility shocks to instrument for age at first birth. Motherhood delay leads to a substantial increase in earnings of 9% per year of delay, an increase in wages of 3%, and an increase in work hours of 6%. Supporting a human capital story, the advantage is largest for college-educated women and those in professional and managerial occupations. Panel estimation reveals both fixed wage penalties and lower returns to experience for mothers, suggesting that a “mommy track” is the source of the timing effect.     

Civic Epistemologies: Constituting Knowledge and Order in Political Communities

How do we know things? The question of epistemology – which drives both the sociology and philosophy of science – is also a crucial question for political sociology. Knowledge is essential to even the most basic and foundational of political processes and institutions. In 2000, for example, the transition of power in the US presidential election hung for 36 days on uncertainty over a seemingly simple question of fact: who won the most votes in Florida? A few years later, disputed factual claims about Iraq's possession of weapons of mass destruction unraveled, calling into question key justifications of the US decision to invade Iraq in 2003 and significantly weakening perceived US legitimacy. Yet, surprisingly, sociologists and political scientists know relatively little about how knowledge gets made in political communities, nor how the making of knowledge is tied to other key aspects of political life, such as identity, authority, legitimacy, and accountability.     

Innovations in child protective services inservice training: commitment to excellence

The overwhelming obstacles to effective CPS intervention created by increasing reports of abuse and neglect, funding shortfalls, and the lack of qualified workers have prompted national efforts to reform the public child welfare system in the United States. Organizations such as the American Public Welfare Association, the Children's Defense Fund, the Child Welfare League of America, and the National Association of Social Workers are currently working closely with other national organizations to develop legislative proposals that will enable child welfare agencies to be more responsive to the needs of children and families. A critical component of this reform is the need to recruit, train, and retain qualified and competent CPS workers. The four training programs described in this article are examples of innovative programs seeking to enhance service delivery by enhancing the knowledge and skills of their staff members. Although the four programs were developed in very different political and social climates and within diverse organizational structures, they all provide useful lessons in how to develop efficient and effective training for workers delivering protective services for children. Any national, state, or local efforts to design and develop new CPS training programs should take into account the significant strides made by these agencies.     

Moments of Inertia and Graph Separators

Graphs that arise from the finite element or finite difference methods often include geometric information such as the coordinates of the nodes of the graph. The geometric separator algorithm of Miller, Teng, Thurston, and Vavasis uses some of the available geometric information to find small node separators of graphs. The algorithm utilizes a random sampling technique based on the uniform distribution to find a good separator. We show that sampling from an elliptic distribution based on the inertia matrix of the graph can significantly improve the quality of the separator. More generally, given a cost function f on the unit d-sphere Ud, we can define an elliptic distribution based on the second moments of f. The expectation of f with respect to the elliptic distribution is less than or equal to the expectation with respect to the uniform distribution, with equality only in degenerate cases. We also demonstrate experimentally that the benefit gained by the use of the additional geometric information is significant. Some previous algorithms have used the moments of inertia heuristically, and suffer from extremely poor worst case performance. This is the first result, to our knowledge, that incorporates the moments of inertia into a provably good strategy.     

Immigrants' Language Skills: The Australian Experience in a Longitudinal Survey

This article is concerned with the determinants of English language proficiency (speaking, reading and writing) among immigrants. It presents a model of immigrant destination language proficiency based on economic incentives, exposure to the destination language, and efficiency in second language acquisition. A unique data set, the Longitudinal Survey of Immigrants to Australia, is used to test the model. This survey had three waves, at about six months, eighteen months and three‐and‐a‐half years after immigration. The analyses are performed by wave, type of language skill and gender using probit analysis. Bivariate probit analysis is used across waves. The hypotheses are supported by the data. The bivariate probit analysis indicates a positive correlation in the unexplained component that declines with time between waves, suggesting a “regression to the mean” in the unobserved components of English language proficiency.