Exclusion restrictions in instrumental variables equations

In this paper we consider two-stage estimators of parameters of a structural equation in a model with recursive exclusion restrictions on the instrumental variables equations. The estimations considered are simple OLS and GLS estimators after substitution of estimates of the systematic part of the IV equations for the endogenous variables. It is known in the literature that neither imposing the restrictions in the first stage nor ignoring them will in general be more efficient than the alternative. We introduce a class of mixed instrumental variables estimators (MIV) with these possibilities as special cases which yields an estimator which is not only more efficient than the two stage estimators considered in the literature but as efficient as an efficient system estimator like 3SLS.     

Picture Perception in Infants: Generalization From Two‐Dimensional to Three‐Dimensional Displays

Two experiments investigated 9‐month‐old infants’ abilities to recognize the correspondence between an actual three‐dimensional (3D) object and its two‐dimensional (2D) representation, looking specifically at representations that did not literally depict the actual object: schematic line drawings. In Experiment 1 , infants habituated to a line drawing of either a doll or a sheep and were then tested with the actual objects themselves. Infants habituated to the sheep drawing recovered to the unfamiliar but not the familiar object, showing a novelty preference. Infants habituated to the doll drawing, however, recovered to both familiar and unfamiliar objects, failing to show any preference between the two. In Experiment 2 , infants habituated to the 3D objects and were then tested with the 2D line drawings. In this case, both groups of infants showed a preference only for the novel displays. Together these findings demonstrate that 9‐month‐old infants recognize the correspondence between 3D objects and their 2D representations, even when these representations are not literal copies of the objects themselves.     

Overlaps and contradictions between queer theory and disability studies

This paper begins by exploring similarities in the experiences of queers and disabled people, such as familial isolation, high rates of violence, stereotypes and discrimination, and the difficulties associated with passing and coming out. Rejecting pathologization and politicizing access as well as using humor and parody as political tools have been important for both movements. The paper then considers similarities and differences in Queer Theory and Disability Studies as intellectual disciplines, by examining their debt to feminism, their opposition to hegemonic normalcy, their strategic use of universalist and minority discourses, their deconstruction of essentialist identity categories and their use of concepts such as performativity.     

Book Review: Welfare Reform,James Madison and Federalism

Public Organization Review -     

Interacting Socially With Human Hands at 24 Months of Age

This experiment explored whether or not 2‐year‐olds would engage in synchronic imitation with human hands. Sixty‐four 24‐month‐old infants participated. In a test of synchronic imitation, infants were given a toy while a model simultaneously performed novel actions on an identical toy. Infants were randomly assigned to 1 of 4 model conditions: a familiar person, an unfamiliar person, disembodied human hands, and disembodied robotic pincers. Infants were as likely to synchronically imitate disembodied hands as a person. Imitation of the pincers was significantly lower. This pattern suggests that 2‐year‐olds will engage socially with human hands in the absence of the rest of the body.     

TALKING ABOUT SEX: Religion and Patterns of Parent–Child Communication about Sex and Contraception

Despite the association between religiousness and conservative sexual attitudes, links between religion and patterns of parent–child communication about sex and birth control are largely undocumented. This study examines these relationships using two nationally representative data sets of parents and adolescents. I evaluated a conceptual model of religious influence on the sexual socialization of adolescents. Results suggest that parental public religiosity curbs the frequency of conversations about sex and birth control, and after accounting for conversations about sexual morality, so does parental religious salience. Despite notable relationships with religious affiliation, age, race, and gender still shape parental communication patterns most consistently.     

Development and Consideration of Global Policies for Managing the Future Risks of Poliovirus Outbreaks: Insights and Lessons Learned Through Modeling

The success of the Global Polio Eradication Initiative promises to bring large benefits, including sustained improvements in quality of life (i.e., cases of paralytic disease and deaths avoided) and costs saved from cessation of vaccination. Obtaining and maintaining these benefits requires that policymakers manage the transition from the current massive use of oral poliovirus vaccine (OPV) to a world without OPV and free of the risks of potential future reintroductions of live polioviruses. This article describes the analytical journey that began in 2001 with a retrospective case study on polio risk management and led to development of dynamic integrated risk, economic, and decision analysis tools to inform global policies for managing the risks of polio. This analytical journey has provided several key insights and lessons learned that will be useful to future analysts involved in similar complex decision-making processes.