Who “Fills in” for Siblings and How? A Multilevel Analysis of Personal Network Composition and Its Relationship to Sibling Size1

In the midst of widespread fertility decline, I examine the relationship between sibling number and support network composition using multilevel regression on data from 25 countries. A fundamental structural effect of having fewer siblings is that individuals have a smaller pool of available close‐kin alters with whom to construct support networks. Consequently, networks of people with fewer siblings should be composed of different sorts of relations. Results confirm that such compositional adjustment occurs in systematic ways. Compared to those with three or more siblings, adults with none to two siblings (as separate categories) are more likely to expect support from parents, extended kin, and close friends but not more likely to do so from spouses/partners and children. Single children are also more likely to include neighbors and have smaller‐sized and/or impersonal networks. These findings contradict the primacy of familial ties in social support networks. Moreover, adjustment of support networks towards nonsibling ties occurs in culturally expected ways. Those with fewer siblings are generally only more likely to turn to ties for the types of support typically associated with those relations—parents for instrumental and financial support and friends for emotional support. Single children, however, also violate institutionalized expectations of social support by turning to ties for a wider range of social support. The results suggest that continuing declines in fertility could bring about both reinforcement and rearticulation of the sociocultural framing of close personal relationships. Moreover, consistent with recent research, the results show that personal networks are influenced more by individual‐level than country‐level factors.     

Evaluating Efficiency-Equality Tradeoffs for Mobile Source Control Strategies in an Urban Area

In environmental risk management, there are often interests in maximizing public health benefits (efficiency) and addressing inequality in the distribution of health outcomes. However, both dimensions are not generally considered within a single analytical framework. In this study, we estimate both total population health benefits and changes in quantitative indicators of health inequality for a number of alternative spatial distributions of diesel particulate filter retrofits across half of an urban bus fleet in Boston, Massachusetts. We focus on the impact of emissions controls on primary fine particulate matter (PM_2.5) emissions, modeling the effect on PM_2.5 concentrations and premature mortality. Given spatial heterogeneity in baseline mortality rates, we apply the Atkinson index and other inequality indicators to quantify changes in the distribution of mortality risk. Across the different spatial distributions of control strategies, the public health benefits varied by more than a factor of two, related to factors such as mileage driven per day, population density near roadways, and baseline mortality rates in exposed populations. Changes in health inequality indicators varied across control strategies, with the subset of optimal strategies considering both efficiency and equality generally robust across different parametric assumptions and inequality indicators. Our analysis demonstrates the viability of formal analytical approaches to jointly address both efficiency and equality in risk assessment, providing a tool for decisionmakers who wish to consider both issues.     

Assessing the Precision of Turning Point Estimates in Polynomial Regression Functions

Researchers often report point estimates of turning point(s) obtained in polynomial regression models but rarely assess the precision of these estimates. We discuss three methods to assess the precision of such turning point estimates. The first is the delta method that leads to a normal approximation of the distribution of the turning point estimator. The second method uses the exact distribution of the turning point estimator of quadratic regression functions. The third method relies on Markov chain Monte Carlo methods to provide a finite sample approximation of the exact distribution of the turning point estimator. We argue that the delta method may lead to misleading inference and that the other two methods are more reliable. We compare the three methods using two data sets from the environmental Kuznets curve literature, where the presence and location of a turning point in the income-pollution relationship is the focus of much empirical work.     

The local and global structure of knowledge production in an emergent research field: An exponential random graph analysis

Previous research has characterized knowledge networks by diffuse connectivity and/or clusters and the absence of centrality. In contrast, exponential random graph models used in this article demonstrate that the uncertainty and centralized influence typical of an emerging area of research leads to the creation of a densely interconnecting core that acts to cohere the network. Moreover, eclecticism and innovativeness, also characteristic of a developing area, lead to a diffusely connected structure. The data, comprising 2200 authors and 76 papers have been manually coded from articles on the feminization of the labor force in Asia.     

Maternal neural reactivity during pregnancy predicts infant temperament

Maternal biological systems impact infant temperament as early as the prenatal period, though the mechanisms of this association are unknown. Using a prospective, longitudinal design, we found that maternal (N = 89) amplitudes of the late positive potential (LPP) in response to negative stimuli during the second, but not the third, trimester of pregnancy predicted observed and physiological indices of temperamental reactivity in infants at age 4 months. Maternal LPP was positively associated with observed infant fear and negatively associated with frontal EEG asymmetry and cortisol reactivity in infants at age 4 months. Results identify a putative mechanism, early in pregnancy, for the intergenerational transmission of emotional reactivity from mother to infant.     

Achieving common grounds in communication via interfaces: a role of spatial frames for reference

The current paper argues for synchronising spatial frames of reference for achieving effective multiparty communication in collaborative virtual environments. Synchronising nonverbal behaviour from different modalities is an important step for simulating face-to-face-interaction where all nonverbal cues are available. Such synchronisation also serves as an effective basis for building multimodal interfaces especially if these have to be deployed for multiparty communication. It is argued that common spatial reference frames are helpful in coordinating different points of attention and facilitating work by serving as the springboard for joint attention among members of the team. Consequently, it is desirable to aim for such common grounds and not just focus on coordinating disjointed virtual spaces for facilitating decision-making by reducing felt collaborative effort. Implementing the synchronisation of spatial reference frames for modern technologies thus serves dual purposes by achieving common grounds in communication and maintaining autonomy of each member at the same time. Towards this end, the current paper proposes the concept of decentred egocentric frame, the origin of which is one’s own body and the spatial relation between two objects is defined with respect to this origin. This frame seems to be important for separating each member’s focus from his own body (self/activities) and also helps in coordinating one’s focus with those of the others whether interacting verbally or nonverbally. This is an important conceptual development as the proposed classification is hypothesised to function in a similar manner across different sensory modalities. The paper concludes with issues on implementation and other future conceptual developments.     

What makes a network go round? Exploring the structure of a strong component with exponential random graph models

A strong component is a subgraph in a directed network where, following the direction of ties, all nodes in the graph are reachable from one another. Mutual reachability implies that every node in the graph is theoretically able to send materials to and/or influence every other node suggesting that strong components are amongst the more egalitarian network structures. Despite this intriguing feature, they remain understudied. Using exponential random graph models (ERGM) for directed networks, we investigate the social and structural processes underlying the generation of strong components. We illustrate our argument using a network of 301 nodes and 703 personal lending ties from Renaissance Florence. ERGM shows that our strong component arises from triadic clustering alongside an absence of higher-order star structures. We contend that these processes produce a strong component with a hierarchical, rather than an egalitarian structure: while some nodes are deeply embedded in a dense network of exchange, the involvement of others is more tenuous. More generally, we argue that such tiered core-periphery strong components will predominate in networks where the social context creates conditions for an absence of preferential attachment alongside the presence of localized closure. Although disparate social processes can give rise to hierarchical strong components linked to these two structural mechanisms, in Florence they are associated with the presence of multiple dimensions of social status and the connectedness of participants across disparate network domains.     

Female management,overconfidence and debt maturity: European evidence

Journal of Management and Governance - This paper investigates how female involvement in management shapes the nature of the firm’s financial decisions in terms of debt maturity. It is...     

Seven‐Month‐Old Infants Selectively Reproduce the Goals of Animate But Not Inanimate Agents

We tested 7‐month‐old infants' sensitivity to others' goals in an imitation task, and assessed whether infants are as likely to imitate the goals of nonhuman agents as they are to imitate human goals. In the current studies, we used the paradigm developed by Hamlin et. al (in press) to test infants' responses to human actions versus closely matched inanimate object motions. The experimental events resembled those from Luo and Baillargeon's (2005) looking‐time study in which infants responded to the movements of an inanimate object (a self‐propelled box) as goal‐directed. Although infants responded visually to the goal structure of the object's movement, here they did not reproduce the box's goal. These results provide further evidence that 7‐month‐olds' goal representations are sufficiently robust to drive their own manual actions. However, they indicate that infants' responses to inanimate object movements may not be robust in this way.