2,897 research outputs found

    A meta-analytic assessment of the effect of immigration on wages

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    In our increasingly interconnected and open world, international migration is becoming an important socio-economic phenomenon for many countries. Since the early 1980s, many studies have been undertaken of the impact of immigration on host labour markets. Borjas (2003) noted that the estimated effect of immigration on the wage of native workers varies widely from study to study and sometimes even within the same study. In addition, these effects cluster around zero. Such a small effect is a rather surprising outcome, given that in a closed competitive labour market an increase in labour supply may be expected to exert a downward pressure on wages. We revisit this issue by applying meta-analytic techniques to a sample of eighteen papers, which altogether generated 348 estimates of the percentage change in the wage of a native worker with respect to a one percentage point increase in the ratio of immigrants over native workers. While many studies in our sample employ US data, estimates are also obtained from Germany, The Netherlands, France, Norway, Austria, Israel and Australia. Our analysis shows that results vary across countries and are inter alia related to the type of modelling approach. Technical issues such as publication bias and quality of the estimates are addressed as well. A negative but small effect of immigration on wages of native groups with similar skills appears rather robust

    Two-Point Entanglement Near a Quantum Phase Transition

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    In this work, we study the two-point entanglement S(i,j), which measures the entanglement between two separated degrees of freedom (ij) and the rest of system, near a quantum phase transition. Away from the critical point, S(i,j) saturates with a characteristic length scale ξE\xi_E, as the distance |i-j| increases. The entanglement length ξE\xi_E agrees with the correlation length. The universality and finite size scaling of entanglement are demonstrated in a class of exactly solvable one dimensional spin model. By connecting the two-point entanglement to correlation functions in the long range limit, we argue that the prediction power of a two-point entanglement is universal as long as the two involved points are separated far enough.Comment: published versio

    Responses of Drosophila giant descending neurons to visual and mechanical stimuli

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    In Drosophila, the paired giant descending neurons (GDNs), also known as giant fibers, and the paired giant antennal mechanosensory descending neurons (GAMDNs), are supplied by visual and mechanosensory inputs. Both neurons have the largest cell bodies in the brain and both supply slender axons to the neck connective. The GDN axon thereafter widens to become the largest axon in the thoracic ganglia, supplying information to leg extensor and wing depressor muscles. The GAMDN axon remains slender, interacting with other descending neuron axons medially. GDN and GAMDN dendrites are partitioned to receive inputs from antennal mechanosensory afferents and inputs from the optic lobes. Although GDN anatomy has been well studied in Musca domestica, less is known about the Drosophila homolog, including electrophysiological responses to sensory stimuli. Here we provide detailed anatomical comparisons of the GDN and the GAMDN, characterizing their sensory inputs. The GDN showed responses to light-on and light-off stimuli, expanding stimuli that result in luminance decrease, mechanical stimulation of the antennae, and combined mechanical and visual stimulation. We show that ensembles of lobula columnar neurons (type Col A) and mechanosensory antennal afferents are likely responsible for these responses. The reluctance of the GDN to spike in response to stimulation confirms observations of the Musca GDN. That this reluctance may be a unique property of the GDN is suggested by comparisons with the GAMDN, in which action potentials are readily elicited by mechanical and visual stimuli. The results are discussed in the context of descending pathways involved in multimodal integration and escape responses

    Expert chess memory: Revisiting the chunking hypothesis

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    After reviewing the relevant theory on chess expertise, this paper re-examines experimentally the finding of Chase and Simon (1973a) that the differences in ability of chess players at different skill levels to copy and to recall positions are attributable to the experts' storage of thousands of chunks (patterned clusters of pieces) in long-term memory. Despite important differences in the experimental apparatus, the data of the present experiments regarding latencies and chess relations between successively placed pieces are highly correlated with those of Chase and Simon. We conclude that the 2-second inter-chunk interval used to define chunk boundaries is robust, and that chunks have psychological reality. We discuss the possible reasons why Masters in our new study used substantially larger chunks than the Master of the 1973 study, and extend the chunking theory to take account of the evidence for large retrieval structures (templates) in long-term memory

    Neighborhood effects and parental involvement in the intergenerational transmission of education

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    We analyze the intergenerational transmission of education focusing on the interplay between family and neighborhood effects. We develop a theoretical model suggesting that both neighborhood quality and parental effort are of importance for the education attained by children. This model proposes a mechanism explaining why and how they are of importance, distinguishing between high- and low-educated parents. We then bring this model to the data using a longitudinal data set in Britain. The available information on social housing in big cities allows us to identify the role of neighbourhood in educational outcomes. We find that the better is the quality of the neighborhood, the higher is the parents’ involvement in their children’s education. A novel finding with respect to previous US studies is that family is of importance for children with highlyeducated parents while it is the community that is crucial for the educational achievement of children from low-educated families

    MATERNAL EDUCATION, HOME ENVIRONMENTS, AND THE DEVELOPMENT OF CHILDREN AND ADOLESCENTS

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    We study the intergenerational effects of maternal education on children's cognitive achievement, behavioral problems, grade repetition, and obesity, using matched data from the female participants of the National Longitudinal Survey of Youth 1979 (NLSY79) and their children. We address the endogeneity of maternal schooling by instrumenting it with variation in schooling costs during the mother's adolescence. Our results show substantial intergenerational returns to education. Our data set allows us to study a large array of channels which may transmit the effect of maternal education to the child, including family environment and parental investments at different ages of the child. We discuss policy implications and relate our findings to the literature on intergenerational mobility. © 2012 by the European Economic Association

    Do returns to education depend on how and whom you ask?

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    Returns to education remain an important parameter of interest in economic analysis. A large literature estimates these returns, often carefully addressing issues such as selection into wage employment and endogeneity in terms of completed schooling. There has been much less exploration of whether the estimates of Mincerian returns depend on how information about wage work is collected. Relying on a survey experiment in Tanzania, this paper finds that estimates of the returns to education vary by questionnaire design, but not by whether the information on employment and wages is self-reported or collected by a proxy respondent. The differences derived from questionnaire type are substantial, varying from higher returns of 5 percentage points among the most well educated men to 16 percentage points among the least well educated women. These differences are at magnitudes similar to the bias in ordinary least squares estimation, which receives considerable attention in the literature. The findings demonstrate that survey design matters in the estimation of returns to schooling and that care is needed in comparing across contexts and over time, particularly if the data are generated through different surveys

    Investigating hyper-vigilance for social threat of lonely children

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    The hypothesis that lonely children show hypervigilance for social threat was examined in a series of three studies that employed different methods including advanced eye-tracking technology. Hypervigilance for social threat was operationalized as hostility to ambiguously motivated social exclusion in a variation of the hostile attribution paradigm (Study 1), scores on the Children’s Rejection-Sensitivity Questionnaire (Study 2), and visual attention to socially rejecting stimuli (Study 3). The participants were 185 children (11 years-7 months to 12 years-6 months), 248 children (9 years-4 months to 11 years-8 months) and 140 children (8 years-10 months to 12 years-10 months) in the three studies, respectively. Regression analyses showed that, with depressive symptoms covaried, there were quadratic relations between loneliness and these different measures of hypervigilance to social threat. As hypothesized, only children in the upper range of loneliness demonstrated elevated hostility to ambiguously motivated social exclusion, higher scores on the rejection sensitivity questionnaire, and disengagement difficulties when viewing socially rejecting stimuli. We found that very lonely children are hypersensitive to social threat

    Thermal simulation software outputs: a conceptual data model of information presentation for building design decision-making

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    Building simulation outputs are inherently complex and numerous. Extracting meaningful information from them requires knowledge which mainly resides only in the hands of experts. Initiatives to address this problem tend either to provide very constrained output data interfaces or leave it to the user to customize data organisation and query. This work proposes a conceptual data model from which meaningful dynamic thermal simulation information for building design decision-making may be constructed and presented to the user. It describes how the model was generated and can become operational, with examples of its applications to practical problems. The paper therefore contains useful information for software developers to help in specifying and designing simulation outputs which better respond to building designers’ needs
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