Low-scale inflation in a model of dark energy and dark matter

We present a complete particle physics model that explains three major problems of modern cosmology: inflation, dark matter and dark energy, and also gives a mechanism for leptogenesis. The model has a new gauge group $SU(2)_Z$ that grows strong at a scale $\Lambda\sim 10^{-3}$ eV. We focus on the inflationary aspects of the model. Inflation occurs with a Coleman-Weinberg potential at a low scale, down to \sim 6\times 10^5\gev, being compatible with observational data.Comment: 5 two-column pages, RevTex4; two reference added and minor changes made in the text; published in JCA

L’instabilité structurelle dans le modèle de croissance avec ressource non renouvelable

The analysis of the question of structural stability in the growth model with exhaustible resources consists essentially in the examination of the long term values of capital and consumption as they result from parametric variations. The parameters used in this study relate to ethic (discount rate) and to technology (elasticity of substitution between resource and capital and technical progress). Considering the structural stability, the already known results are generalized in two directions. First, a general description of production technology is made. Second, a special attention is given to the question of technological innovation. An analysis of the form of the Hicksian neutral technical progress is made considering an economy with a Cobb-Douglas production function

Mining and Incentive Concession Contracts

This paper studies the design of a mining concession contract as a multi-period autoselection problem where production is the depletion of a non renewable resource. As compared to symmetric information, we show that overproduction (resp. underproduction) is optimal in the initial phase (resp. terminal phase ) of the resource extraction program. Also, asymmetric information lengthens the contract duration but reduces the scarcity rent. Finally, when there are several agents competing for contract bid, we show that optimal auctioning could be used to award the concession, assigning the lowest cost agent to carry out the extraction.ADVERSE SELECTION; EXHAUSTIBILITY; OVERPRODUCTION

L’instabilité structurelle dans le modèle de croissance avec ressource non renouvelable

The analysis of the question of structural stability in the growth model with exhaustible resources consists essentially in the examination of the long term values of capital and consumption as they result from parametric variations. The parameters used in this study relate to ethic (discount rate) and to technology (elasticity of substitution between resource and capital and technical progress). Considering the structural stability, the already known results are generalized in two directions. First, a general description of production technology is made. Second, a special attention is given to the question of technological innovation. An analysis of the form of the Hicksian neutral technical progress is made considering an economy with a Cobb-Douglas production function.

Déterminants de l’utilisation des services médicaux en régime d’assurance-maladie

Under the regime of public health insurance, the utilization of health cares are determined by various socio-demographic and economic characteristics of the beneficiaries. These determinants are estimated in this study where we apply the dummy variable regression technique to the AMULET data bank, a 1971 cross-section of 8,608 beneficiaries in the province of Québec where most of health cares are free. In increasing order of importance, we find that :i) The individual utilization of health care is increasing with the age of beneficiaries and is higher for women than for the men for the age-group 15-50 years. This tendency is reversed for the age-group 50 years and older since the rate of increase in utilization is higher for men. There is, however, any significant difference in utilization on the basis of sex discrimination for the age-group 0-15 years. The structure age-sex, being of course a proxy of the health status of the beneficiaries, is the most important determinant of health cares utilization. ii) Individual utilization depends on the income class to which belongs the beneficiary. The beneficiaries of the highest and the lowest income class utilize more health care than those belonging to the so called "middle class". Notice however that the lowest income class in the data sample is composed in majority of aged beneficiaries.iii) The size of the beneficiaries' family is not a significant determinant of the utilization of health care for children of age-group 0-15 years. For other age-group however, utilization decreases with this family size for men, but increases for women. iv) The geographic area where the beneficiaries are identified is a weak determinant of utilization. Beneficiaries in urban area utilize more of health care than those living in rural area