Access to health care, medical progress and the emergence of the longevity gap: A general equilibrium analysis

We study skill- and income-related differences in the access to health care as drivers of longevity inequality from a theoretical life-cycle as well as from a macroeconomic perspective. To do so, we develop an overlapping generations model populated by heterogeneous agents subject to endogenous mortality. We model two groups of individuals for whom differences in skills translate into differences in income and in the ability to use medical technology effectively in curbing mortality. We derive the skill- and age-specific individual demand for health care based on the value of life, the level of medical technology and the market prices. Calibrating the model to the development of the US economy and the longevity gap between the skilled and unskilled, we study the impact of rising effectiveness of medical care in improving individual health and examine how disparities in health care utilisation and mortality emerge as a consequence. In so doing, we explore the role of skill-biased earnings growth, skill-bias in the ability to access state-of-the art health care and to use it effectively, and skill-related differences in health insurance coverage. We pay attention to the macroeconomic feedback, especially to medical price inflation. Our findings indicate that skill-bias related to the effectiveness of health care explains a large part of the increase in the longevity with earnings-related differences in the utilisation of health care taking second place. Both channels tend to be reinforced by medical progress

Health insurance, endogenous medical progress, health expenditure growth, and welfare

We study the impact of health insurance expansion on medical spending, longevity and welfare in an OLG economy in which individuals purchase health care to lower mortality and medical progress is profit-driven. Three sectors are considered: final goods production; a health care sector, selling medical services to individuals; and an R&D sector, selling increasingly effective medical technology to the health care sector. We calibrate the model to the development of the US economy/health care system from 1965 to 2005 and study numerically the impact of the insurance expansion. We find that more extensive health insurance accounts for a large share of the rise in US health spending but also boosts the rate of medical progress. A welfare analysis shows that while the subsidization of health care through health insurance creates excessive health care spending, the gains in life expectancy brought about by induced medical progress more than compensate for this

Natural disturbance impacts on trade-offs and co-benefits of forest biodiversity and carbon

With accelerating environmental change, understanding forest disturbance impacts on trade-offs between biodiversity and carbon dynamics is of high socio-economic importance. Most studies, however, have assessed immediate or short-term effects of disturbance, while long-term impacts remain poorly understood. Using a tree-ring-based approach, we analysed the effect of 250 years of disturbances on present-day biodiversity indicators and carbon dynamics in primary forests. Disturbance legacies spanning centuries shaped contemporary forest co-benefits and trade-offs, with contrasting, local-scale effects. Disturbances enhanced carbon sequestration, reaching maximum rates within a comparatively narrow post-disturbance window (up to 50 years). Concurrently, disturbance diminished aboveground carbon storage, which gradually returned to peak levels over centuries. Temporal patterns in biodiversity potential were bimodal; the first maximum coincided with the short-term post-disturbance carbon sequestration peak, and the second occurred during periods of maximum carbon storage in complex old-growth forest. Despite fluctuating local-scale trade-offs, forest biodiversity and carbon storage remained stable across the broader study region, and our data support a positive relationship between carbon stocks and biodiversity potential. These findings underscore the interdependencies of forest processes, and highlight the necessity of large-scale conservation programmes to effectively promote both biodiversity and long-term carbon storage, particularly given the accelerating global biodiversity and climate crises

Sintering mechanisms of metals under electric currents

International audienceThis chapter concerns the microscopic mechanisms involved in densifi-cation of metallic powders submitted to high electric current pulses like in the SPS technique. Because metallic systems exhibit high electric conductivity, focus is made on evaluating the sensitivity of the densification mechanisms on the current. Thus, a first part is devoted to the influence of electric currents on elementary met-allurgical phenomena (diffusion, plasticity…) which are involved in densification. Then, after recalling the micromechanical models of densification, the SPS kinetics is described, and analyzed in the framework of these models, with emphasis on the role of the current. Finally, theoretical and experimental investigations on electrically induced mechanisms at the scale of the powder particle contacts, are presented: dielectric breakdown of oxide layers, arcs and plasma, Joule overheating, electroplasticity and electromigration. Then, conclusions are drawn on the most probable mechanisms, and on the role of the current

Direct ion beam synthesis of II-VI nanocrystals

Abstract We have studied the direct synthesis of nanoparticles formed by dual implantation of large and equal doses of Cd + S, Zn + Te, Cd + Te or Pb + Te ions into SiO 2 substrate. Grazing incidence small angle X-ray scattering (GI-SAXS), transmittance measurements and Raman spectroscopy were used to investigate implanted composites. The 2D GISAXS patterns suggest the synthesis of nanoparticles already during ion implantation, performed either at 300 or at 77 K, while annealing at higher T causes an increase of the fraction and the average size of synthesized nanoparticles. After high-T annealing both optical methods detected nanocrystals of compound semiconductors CdS, ZnTe or CdTe through the appearance of the respective first optical gaps, E g , in transmittance measurements and characteristic LO peaks in Raman spectra. It is proposed that at high ion doses a fraction of implanted atoms synthesize already during implantation into amorphous aggregates of compound semiconductor, which transform into crystalline nanoparticles after annealing

The evolution of the morphology of Ge nanocrystals formed by ion implantation in SiO2

Grazing incidence small angle X-ray scattering was applied to study the synthesis and growth of Ge quantum dots in Ge-implanted SiO2. Ge ion doses were up to 10(17)/cm(2), and subsequent annealing temperatures up to T-a = 1000 degrees C. Results suggest that ordered and correlated Ge QDs can be achieved by high-dose implantation followed by medium-T annealing