1,708 research outputs found

    Counterfactual Distribution Dynamics across European Regions

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    This paper proposes a methodology which combines elements of parametric regression analysis with the nonparametric distribution dynamics approach in order to analyse the role of some variables in the convergence of productivity across European regions over the period 1980-2002. We find that the initial productivity crucially accounts in the convergence process across European regions. Differently, employment growth seems not to play a role, while the Structural and Cohesion Funds seem to play a positive role, even though such effect seems to be very low and statistically significant only at the low bound of the range of initial productivity. The structural change of regional economies plays a positive role, but such effect is statistically significant only for the least productive regions. The output composition of a region in 1980 affects the convergence process of productivity growth in several ways. In particular, the share of non market services on output acts like a source of convergence from 1980 to 2002 but in the long-run it plays a negligible role. Finally, the share of finance acts like a force of divergence across European regions, especially for the least productive regions

    On the Determinants of Distribution Dynamics

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    n this paper we propose a novel approach to identify the impact of growth determinants on the distribution dynamics of productivit y. Our approach integrates counterfactual analysis with the estima tion of stochastic kernels. The counterfactuals are constructed from a semi-parametric growth regression, in which the cross-section heterogeneity in the growth determinants is removed. The methodology also allows us to test for potential distributional effects in the residuals. We illustrate the usefulness of the proposed methodology by an application to a cross-section of countries, which highlights the significant impact on inequality and polarization in the world productivity distribution of growth determinants from an augmented Solow model

    On the Determinants of Distribution Dynamics

    Get PDF
    n this paper we propose a novel approach to identify the impact of growth determinants on the distribution dynamics of productivit y. Our approach integrates counterfactual analysis with the estima tion of stochastic kernels. The counterfactuals are constructed from a semi-parametric growth regression, in which the cross-section heterogeneity in the growth determinants is removed. The methodology also allows us to test for potential distributional effects in the residuals. We illustrate the usefulness of the proposed methodology by an application to a cross-section of countries, which highlights the significant impact on inequality and polarization in the world productivity distribution of growth determinants from an augmented Solow model

    Deep and Proximate Determinants of the World Income Distribution

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    This paper studies the deep and proximate determinants of the evolution of the cross-country distribution of GDP per worker in the period 1960–2008 by a novel method based on an information criterion. We find that countries of our sample follow three distinctive growth regimes identified by two deep determinants, namely life expectancy at birth in 1960 and the share of Catholics in 1965, and that each regime is characterized by non-linearities. Growth regimes appear to be the main cause of the increased inequality and polarization, while technological catch-up, proxied by the initial level of GDP per worker, acts in the opposite direction. Finally, human capital marginally reduces polarization, while investment rates and employment growth have no distributional effect

    A techno-economic approach for decision-making in metal additive manufacturing: metal extrusion versus single and multiple laser powder bed fusion

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    This work presents a decision-making methodology that allows the merging of quantitative and qualitative decision variables for selecting the optimal metal Additive Manufacturing (AM) technology. The approach is applied on two competing technologies in the field of metal AM industry, i.e., the metal extrusion AM process (metal FFF) and the Laser Powder Bed Fusion process (LPBF) with single and multiple lasers, which represent the benchmark solution currently on the market. A comprehensive techno-economical comparison is presented where the two processes are analysed in terms of process capabilities (quality, easiness of use, setup time, range of possible materials, etc.) and costs, considering two different production scenarios and different parts’ geometries. In the first scenario, the AM system is assumed to be dedicated to one single part production while in this second scenario, the AM system is assumed to be saturated, as devoted to producing a wide mix of part types. For each scenario, two different part types made of 17–4 PH stainless steel are considered as a reference to investigate the effect of shape complexity, part size and production times to select the best technology when metal FFF and LPBF must be considered. The first part type refers to an extrusion die, to represent typical shapes of interest in the tooling industry, while the second part type is an impeller which can be used in many different industrial sectors, ranging from oil and gas to aerospace. In order to include quantitative and qualitative criteria, a decision-making model based on Analytic Hierarchy Process (AHP) is proposed as the enabler tool for decision making. The proposed approach allows to determine the most effective solution depending on the different production configurations and part types and can be used as a guideline and extended to include other technologies in the field of metal AM. On the other side, the critical discussion of the criteria selected, and the results achieved allow to highlight the pros and cons of the competing technologies, thus defining the existing limits to define directions for future research

    Prevalence and Trends in Transmitted and Acquired Antiretroviral Drug Resistance, Washington, DC, 1999-2014.

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    Background Drug resistance limits options for antiretroviral therapy (ART) and results in poorer health outcomes among HIV-infected persons. We sought to characterize resistance patterns and to identify predictors of resistance in Washington, DC. Methods We analyzed resistance in the DC Cohort, a longitudinal study of HIV-infected persons in care in Washington, DC. We measured cumulative drug resistance (CDR) among participants with any genotype between 1999 and 2014 (n = 3411), transmitted drug resistance (TDR) in ART-naïve persons (n = 1503), and acquired drug resistance (ADR) in persons with genotypes before and after ART initiation (n = 309). Using logistic regression, we assessed associations between patient characteristics and transmitted resistance to any antiretroviral. Results Prevalence of TDR was 20.5%, of ADR 40.5%, and of CDR 45.1% in the respective analysis groups. From 2004 to 2013, TDR prevalence decreased for nucleoside and nucleotide analogue reverse transcriptase inhibitors (15.0 to 5.5%; p = 0.0003) and increased for integrase strand transfer inhibitors (INSTIs) (0.0–1.4%; p = 0.04). In multivariable analysis, TDR was not associated with age, race/ethnicity, HIV risk group, or years from HIV diagnosis. Conclusions In this urban cohort of HIV-infected persons, almost half of participants tested had evidence of CDR; and resistance to INSTIs was increasing. If this trend continues, inclusion of the integrase-encoding region in baseline genotype testing should be strongly considered

    The IkB kinase inhibitor nuclear factor-kB essential modulator–binding domain peptide for inhibition of balloon injury-induced neointimal formation

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    Objective—The activation of nuclear factor-kB (NF-kB) is a crucial step in the arterial wall’s response to injury. The identification and characterization of the NF-kB essential modulator– binding domain (NBD) peptide, which can block the activation of the IkB kinase complex, have provided an opportunity to selectively abrogate the inflammation-induced activation of NF-kB. The aim of the present study was to evaluate the effect of the NBD peptide on neointimal formation.<br></br> Methods and Results—In the rat carotid artery balloon angioplasty model, local treatment with the NBD peptide (300 microg/site) significantly reduced the number of proliferating cells at day 7 (by 40%; P<0.01) and reduced injury-induced neointimal formation (by 50%; P<0.001) at day 14. These effects were associated with a significant reduction of NF-kB activation and monocyte chemotactic protein-1 expression in the carotid arteries of rats treated with the peptide. In addition, the NBD peptide (0.01 to 1 micromol/L) reduced rat smooth muscle cell proliferation, migration, and invasion in vitro. Similar results were observed in apolipoprotein E-/-, mice in which the NBD peptide (150 microg/site) reduced wire-induced neointimal formation at day 28 (by 47%; P<0.01).<br></br> Conclusion—The NBD peptide reduces neointimal formation and smooth muscle cell proliferation/migration, both effects associated with the inhibition of NF-kB activation
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