Interpreting the evidence on life cycle skill formation

This paper presents economic models of child development that capture the essence of recent findings from the empirical literature on skill formation. The goal of this essay is to provide a theoretical framework for interpreting the evidence from a vast empirical literature, for guiding the next generation of empirical studies, and for formulating policy. Central to our analysis is the concept that childhood has more than one stage. We formalize the concepts of self-productivity and complementarity of human capital investments and use them to explain the evidence on skill formation. Together, they explain why skill begets skill through a multiplier process. Skill formation is a life cycle process. It starts in the womb and goes on throughout life. Families play a role in this process that is far more important than the role of schools. There are multiple skills and multiple abilities that are important for adult success. Abilities are both inherited and created, and the traditional debate about nature versus nurture is scientiÞcally obsolete. Human capital investment exhibits both self-productivity and complementarity. Skill attainment at one stage of the life cycle raises skill attainment at later stages of the life cycle (self-productivity). Early investment facilitates the productivity of later investment (complementarity). Early investments are not productive if they are not followed up by later investments (another aspect of complementarity). This complementarity explains why there is no equity-efficiency trade-off for early investment. The returns to investing early in the life cycle are high. Remediation of inadequate early investments is difficult and very costly as a consequence of both self-productivity and complementarity

Using the Lane-Change Test (LCT) to Assess Distraction: Tests of Visual-Manual and Speech-Based Operation of Navigation System Interfaces

The Lane Change Test (LCT) is an easy-to-implement, low-cost methodology for the evaluation of the distraction associated with performing invehicle tasks while driving (Mattes, 2003). In the present study, the LCT was used to assess driving performance when drivers completed navigation tasks using visual-manual or speech-based interfaces. Drivers performed two types of navigation tasks at two levels of difficulty. The results provide support for the LCT as an effective measure of distraction for both types of interface. It is recommended that the LCT procedure incorporate additional measures beyond the current mean deviation measure. Two measures are suggested: Lane Change Initiation, which reflects the aspects of driving having to do with detection and response delay as a result of distraction, and a measure of task duration to account for risk exposure

Education, Work, and Crime: Theory and Evidence.

This paper develops and empirically examines a dynamic model of decisions to work, invest in human capital, and commit crime. By making all three activities endogenous, the model makes a number of new and interesting contributions to the study of crime. First, the model explains why older, more intelligent, and more educated workers tend to commit less of some property crimes than others. Second, the model is useful for analyzing the impacts of education, training, and work subsidies on criminal behavior. Third, unobserved age differences in on-the-job skill investment explain why wages and crime are more negatively correlated at older ages. Fourth, the model predicts a rise in youth crime should accompany the recent rise in returns to skills. Finally, the model suggests that law enforcement policies increase education, training and labor supply, while reducing criminal activity.EDUCATION ; CRIMES ; WORK

A Frequency-Controlled Magnetic Vortex Memory

Using the ultra low damping NiMnSb half-Heusler alloy patterned into vortex-state magnetic nano-dots, we demonstrate a new concept of non-volatile memory controlled by the frequency. A perpendicular bias magnetic field is used to split the frequency of the vortex core gyrotropic rotation into two distinct frequencies, depending on the sign of the vortex core polarity $p=\pm1$ inside the dot. A magnetic resonance force microscope and microwave pulses applied at one of these two resonant frequencies allow for local and deterministic addressing of binary information (core polarity)

Walverine: A Walrasian Trading Agent

TAC-02 was the third in a series of Trading Agent Competition events fostering research in automating trading strategies by showcasing alternate approaches in an open-invitation market game. TAC presents a challenging travel-shopping scenario where agents must satisfy client preferences for complementary and substitutable goods by interacting through a variety of market types. Michigan's entry, Walverine, bases its decisions on a competitive (Walrasian) analysis of the TAC travel economy. Using this Walrasian model, we construct a decision-theoretic formulation of the optimal bidding problem, which Walverine solves in each round of bidding for each good. Walverine's optimal bidding approach, as well as several other features of its overall strategy, are potentially applicable in a broad class of trading environments.trading agent, trading competition, tatonnement, competitive equilibrium

Identification of oral clefts as a risk factor for hearing loss during newborn hearing screening

Objective: This study assessed whether children with oral clefts are appropriately classified as at-risk for hearing loss at the time of newborn hearing screening and describes their screening and diagnostic results. Design: Birth certificates were used to identify children with cleft lip and palate or isolated cleft palate born in Washington State from 2008–2013. These were cross-referenced with the state’s Early Hearing Detection, Diagnosis and Intervention (EHDDI) database. Multivariate logistic regression was used to examine associations. Results: Birth records identified 235 children with cleft lip and palate and 116 with isolated cleft palate. Six children were listed as having both diagnoses. Only 138 (39%) of these children were designated as having a craniofacial anomaly in the EHDDI database. Children who were misclassified were less likely to have referred on initial hearing screening, OR 0.3, 95% CI [0.2, 0.5]. Misclassification of risk factor status was also associated with delayed hearing screening past 30 days of age or unknown age at screening, OR 4.4, 95% CI [1.5, 13.3], p = 0.008. Of 50 children with diagnostic results; 25 (50%) had hearing loss: 18 conductive, 2 mixed, and 5 unspecified. Conclusion: A majority of children with oral clefts were misclassified regarding risk factor for hearing loss in the EHDDI database

Enhancement of the superconducting gap by nesting in CaKFe4As4 - a new high temperature superconductor

We use high resolution angle resolved photoemission spectroscopy and density functional theory with experimentally obtained crystal structure parameters to study the electronic properties of CaKFe4As4. In contrast to related CaFe2As2 compounds, CaKFe4As4 has high Tc of 35K at stochiometric composition. This presents unique opportunity to study properties of high temperature superconductivity of iron arsenic superconductors in absence of doping or substitution. The Fermi surface consists of three hole pockets at $\Gamma$ and two electron pockets at the $M$ point. We find that the values of the superconducting gap are nearly isotropic, but significantly different for each of the FS sheets. Most importantly we find that the overall momentum dependence of the gap magnitudes plotted across the entire Brillouin zone displays a strong deviation from the simple cos(kx)cos(ky) functional form of the gap function, proposed in the scenario of the Cooper-pairing driven by a short range antiferromagnetic exchange interaction. Instead, the maximum value of the gap is observed for FS sheets that are closest to the ideal nesting condition in contrast to the previous observations in some other ferropnictides. These results provide strong support for the multiband character of superconductivity in CaKFe4As4, in which Cooper pairing forms on the electron and the hole bands interacting via dominant interband repulsive interaction, enhanced by FS nesting}.Comment: 5 pages, 4 figure