3,396 research outputs found

    Barro's fertility equations: the robustness of the role of female education and income

    Get PDF
    Barro and Lee (1994) and Barro and Sala-i-Martin (1995) find that real per-capita GDP and both male and female education have important effects on fertility in their cross-country empirical studies. In order to assess the robustness of their results, their estimated models are subjected to specification and diagnostic testing, the effects on the model of using the improved Barro and Lee (1996) cross-country data on educational attainment of the population aged 15 and over are examined, and the different specifications used by Barro and Lee and by Barro and Sala-i-Martin compared. The results obtained suggest that their fertility equations do not perform well in terms of diagnostic testing, and are very sensitive to the use of different vintages of the educational attainment proxies and of the Summers-Heston cross-country income data. A robust explanation of fertility, to link with empirical growth equations, has, therefore, not yet been found; further work is required in this area

    Optimal Economic Growth under Stochastic Environmental Impact: Sensitivity Analysis

    Get PDF
    In this work we present an approach toward the sensitivity analysis of optimal economic growth to a negative environmental impact driven by random natural hazards that damage the production output . We use a simplified model of the GDP whose growth leads to the increase of GHG in the atmosphere provided investment in cleaning is insufficient. The hypothesis of the Poisson probability distribution of the natural hazards is used at the first stage of the research. We apply the standard utility function - the discounted integral consumption and construct an optimal investment policy in production and cleaning together with optimal GDP trajectories. We calibrate the model in the global scale and analyze the sensitivity of obtained optimal growth scenarios with respect to uncertain parameters of the Poisson distribution

    Spatially resolved kinematics in the central 1 kpc of a compact star-forming galaxy at z=2.3 from ALMA CO observations

    Get PDF
    We present high spatial resolution (FWHM\sim0.14'') observations of the CO(878-7) line in GDS-14876, a compact star-forming galaxy at z=2.3z=2.3 with total stellar mass of log(M/M)=10.9\log(M_{\star}/M_{\odot})=10.9. The spatially resolved velocity map of the inner r1r\lesssim1~kpc reveals a continous velocity gradient consistent with the kinematics of a rotating disk with vrot(r=1kpc)=163±5v_{\rm rot}(r=1\rm kpc)=163\pm5 km s1^{-1} and vrot/σ2.5v_{\rm rot}/\sigma\sim2.5. The gas-to-stellar ratios estimated from CO(878-7) and the dust continuum emission span a broad range, fgasCO=Mgas/M=1345%f^{\rm CO}_{\rm gas}=M_{\rm gas}/M_{\star}=13-45\% and fgascont=5067%f^{\rm cont}_{\rm gas}=50-67\%, but are nonetheless consistent given the uncertainties in the conversion factors. The dynamical modeling yields a dynamical mass oflog(Mdyn/M)=10.580.2+0.5\log(M_{\rm dyn}/M_{\odot})=10.58^{+0.5}_{-0.2} which is lower, but still consistent with the baryonic mass, log\log(Mbar_{\rm bar}= M_{\star} + MgasCO^{\rm CO}_{\rm gas}/M_{\odot})=11.0=11.0, if the smallest CO-based gas fraction is assumed. Despite a low, overall gas fraction, the small physical extent of the dense, star-forming gas probed by CO(878-7), 3×\sim3\times smaller than the stellar size, implies a strong concentration that increases the gas fraction up to fgasCO,1kpc85%f^{\rm CO, 1\rm kpc}_{\rm gas}\sim 85\% in the central 1 kpc. Such a gas-rich center, coupled with a high star-formation rate, SFR\sim 500 M_{\odot} yr1^{-1}, suggests that GDS-14876 is quickly assembling a dense stellar component (bulge) in a strong nuclear starburst. Assuming its gas reservoir is depleted without replenishment, GDS-14876 will quickly (tdepl27t_{\rm depl}\sim27 Myr) become a compact quiescent galaxy that could retain some fraction of the observed rotational support.Comment: Accepted for Publication in ApJL. Kinematic maps are shown in Figures 2 and

    Variational Worldline Approximation for the Relativistic Two-Body Bound State in a Scalar Model

    Full text link
    We use the worldline representation of field theory together with a variational approximation to determine the lowest bound state in the scalar Wick-Cutkosky model where two equal-mass constituents interact via the exchange of mesons. Self-energy and vertex corrections are included approximately in a consistent way as well as crossed diagrams. Only vacuum-polarization effects of the heavy particles are neglected. In a path integral description of an appropriate current-current correlator an effective, retarded action is obtained by integrating out the meson field. As in the polaron problem we employ a quadratic trial action with variational functions to describe retardation and binding effects through multiple meson exchange.The variational equations for these functions are derived, discussed qualitatively and solved numerically. We compare our results with the ones from traditional approaches based on the Bethe-Salpeter equation and find an enhanced binding contrary to some claims in the literature. For weak coupling this is worked out analytically and compared with results from effective field theories. However, the well-known instability of the model, which usually is ignored, now appears at smaller coupling constants than in the one-body case and even when self-energy and vertex corrections are turned off. This induced instability is investigated analytically and the width of the bound state above the critical coupling is estimated.Comment: 62 pages, 7 figures, FBS style, published versio

    An empirical analysis of patents flows and R&D flows around the world

    Full text link
    In this article, we empirically investigate the effect of Research and Development (R&D) flows on patent flows around the world. We do this using an unbalanced panel consisting primarily of Organization for Economic Co-operation and Development (OECD) countries that have both patent and R&D expenditure information broken down by domestic and foreign sources. Our analysis shows that even among a fairly homogeneous group of countries, the sources of patents and R&D differ substantially. Using a dynamic panel framework, we find that domestic R&D per capita increases domestic patents per capita only for the European Patent Convention (EPC) countries that already have a decentralized approach to innovation. Foreign R&D per capita increases foreign patents per capita in all countries even though foreign R&D constitutes a very small fraction of total R&D. We find that some of these differences can be attributed to the locations of the patent applications, including those to the European Patent Office (EPO), United States Patent and Trademark Office (USPTO) and triadic patent applications to the EPO, USPTO and Japan Patent Office (JPO) simultaneously

    Inequality, Fiscal Capacity and the Political Regime: Lessons from the Post-Communist Transition

    Get PDF
    Using panel data for twenty-seven post-communist economies between 1987-2003, we examine the nexus of relationships between inequality, fiscal capacity (defined as the ability to raise taxes efficiently) and the political regime. Investigating the impact of political reform we find that full political freedom is associated with lower levels of income inequality. Under more oligarchic (authoritarian) regimes, the level of inequality is conditioned by the state’s fiscal capacity. Specifically, oligarchic regimes with more developed fiscal systems are able to defend the prevailing vested interests at a lower cost in terms of social injustice. This empirical finding is consistent with the model developed by Acemoglu (2006). We also find that transition countries undertaking early macroeconomic stabilisation now enjoy lower levels of inequality; we confirm that education fosters equality and the suggestion of Commander et al (1999) that larger countries are prone to higher levels of inequality.http://deepblue.lib.umich.edu/bitstream/2027.42/57211/1/wp831 .pd

    Worker remittances and the global preconditions of ‘smart development’

    Get PDF
    With the growing environmental crisis affecting our globe, ideas to weigh economic or social progress by the ‘energy input’ necessary to achieve it are increasingly gaining acceptance. This question is intriguing and is being dealt with by a growing number of studies, focusing on the environmental price of human progress. Even more intriguing, however, is the question of which factors of social organization contribute to a responsible use of the resources of our planet to achieve a given social result (‘smart development’). In this essay, we present the first systematic study on how migration – or rather, more concretely, received worker remittances per GDP – helps the nations of our globe to enjoy social and economic progress at a relatively small environmental price. We look at the effects of migration on the balance sheets of societal accounting, based on the ‘ecological price’ of the combined performance of democracy, economic growth, gender equality, human development, research and development, and social cohesion. Feminism in power, economic freedom, population density, the UNDP education index as well as the receipt of worker remittances all significantly contribute towards a ‘smart overall development’, while high military expenditures and a high world economic openness are a bottleneck for ‘smart overall development’
    corecore