Optimal health insurance contract : can moral hazard increase indemnity ?.

In this note, we generalize the results obtained by Barday and Lesur (2005) by considering a bivariated non separable utility function. We characterize optimal health insurance contracts. Moreover, we show that under moral hazard a sufficiently high risk aversion implies that the optimal coverage and the optimal preventive effort are higher than with perfect information.Moral hazard; Health insurance; bivariate utility function; health status; optimal contract;

Adverse selection and moral hazard in health insurance.

In this paper, we want to characterize the optimal health insurance contract with adverse selection and moral hazard. We assume that policyholders differ by the permanent health status loss and choose an unobservable preventive effort in order to reduce the probability of illness which is ex-ante identical. The difference in illness'after-effect modifies policyholders' preventive actions. By the way, they differ in probabilities of illness leading to a situation close to Rothschild and Stiglitz 'model. In this case, we show that the optimal contract exhibits a deductible for the high health risk type since a higher after effect implies a higher preventive effort and then a lower probability of illness rather than for the low health risk type.Health insurance; risk; policyholders;

Bifurcations and symmetry breaking in the wake of axisymmetric bodies

We consider the generic problem of wake instabilities past fixed axisymmetric bodies, and focus on the extreme cases of a sphere and a flat disk. Numerical results reveal that the wakes of these two bodies evolve differently as the Reynolds number is increased. Especially, two new vortex shedding modes are identified behind a disk. To interpret these results, we introduce a model based on the theory of mode interactions in presence of O(2) symmetry. This model, which was initially developed for the Taylor–Couette system, allows us to explain the structural differences observed in the evolution of the two types of wakes and to accurately predict the evolution of the lift force

Falling styles of disks

We numerically investigate the dynamics of thin disks falling under gravity in a viscous fluid medium at rest at infinity. Varying independently the density and thickness of the disk reveals the influence of the disk aspect ratio which, contrary to previous belief, is found to be highly significant as it may completely change the route to non-vertical paths as well as the boundaries between the various path regimes. The transition from the straight vertical path to the planar fluttering regime is found to exhibit complex dynamics: a bistable behaviour of the system is detected within some parameter range and several intermediate regimes are observed in which, although the wake is unstable, the path barely deviates from vertical. By varying independently the body-to-fluid inertia ratio and the relative magnitude of inertial and viscous effects over a significant range, we set up a comprehensive map of the corresponding styles of path followed by an infinitely thin disk. We observe the four types of planar regimes already reported in experiments but also identify two additional fully three-dimensional regimes in which the body experiences a slow horizontal precession superimposed onto zigzagging or tumbling motions

Visualizing Object Oriented Software in Three Dimensions

There is increasing evidence that it is possible to perceive and understand increasingly comple x information systems if they are displayed a s graphical objects in a three dimensional space . Object-oriented software provides an interestin g test case - there is a natural mapping fro m software objects to visual objects . In this paper we explore two areas. 1) Information perception : we are running controlled experiments to determine empirically if our initial premise is valid; how much more (or less) can be understoo d in 3D than in 2D? 2) Layout: our strategy is to combine partially automatic layout with manua l layout. This paper presents a brief overview of the project, the software architecture and some preliminary empirical results

Weak-inertial flow between two rough surfaces

“Oseen–Poiseuille” equations are developed from an asymptotic formulation of the three-dimensional Navier–Stokes equations in order to study the influence of weak inertia on flows between rough surfaces. The impact of the first correction on macroscopic flow due to inertia has been determined by solving these equations numerically. From the numerical convergence of the asymptotic expansion to the three-dimensional Navier–Stokes flows, it is shown that, at the macroscopic scale, the quadratic correction to the Reynolds equation in the weak-inertial regime vanishes generalizing a similar result in porous media

A GENERAL EQUILIBRIUM SKILL ACQUISITIONS MODEL OF DEVELOPMENT FOR LESOTHO

Dual economy, large unemployment, a fixed number of skilled workers, perfect capital mobility, migrant labor force working in South African gold mines, and a cycle of poverty characterize Lesotho. This paper develops a general equilibrium model for Lesotho specifying these absorbing economic characteristics. We are particularly interested in constructing a rising step skill acquisition function, which shows that small infusions of human-capital investment would not pull the economy out of its poverty trap, but a large infusion would.Lesotho, Skill Acquisition, Human Capital, Economic Development, General Equilibrium

Dynamic behavior and microstructural properties of cancellous bone

The aim of the presented study is to identify some properties of the dynamic behavior of the cancellous bone and to identify the link between this mechanical behavior and the microstructural properties. 7 cylinders of bovine cancellous bone (diameter 41 mm, thickness 14 mm) were tested in quasi static loading (0.001 s-1), 8 in dynamic loading (1000 s-1) and 10 in dynamic loading (1500 s-1) with a confinement system. All the specimens were submitted to imaging before the tests (pQCT) in order to indentify two microstructural properties: Bone Volume / Total Volume ? BV/TV ? and Trabeculae Thickness ? Tb.Th. The behavior of bovine cancellous bone under compression exhibits a foam-type behavior over the whole range of strain rates explored in this study. The results show that for the quasi-static tests only the stresses are correlated with BV/TV. For the unconfined dynamic tests, the yield stress is correlated to BV/TV and the plateau stress to BV/TV and Tb.Th. For the confined tests, only the plateau stress is correlated to BV/TV and Tb.Th. The effect of strain rate is an increase of the yield stress and the plateau stress. The confinement has an effect on the measured values of compression stresses that confirms the importance of marrow flow in the overall behavior

High-order implicit palindromic discontinuous Galerkin method for kinetic-relaxation approximation

We construct a high order discontinuous Galerkin method for solving general hyperbolic systems of conservation laws. The method is CFL-less, matrix-free, has the complexity of an explicit scheme and can be of arbitrary order in space and time. The construction is based on: (a) the representation of the system of conservation laws by a kinetic vectorial representation with a stiff relaxation term; (b) a matrix-free, CFL-less implicit discontinuous Galerkin transport solver; and (c) a stiffly accurate composition method for time integration. The method is validated on several one-dimensional test cases. It is then applied on two-dimensional and three-dimensional test cases: flow past a cylinder, magnetohydrodynamics and multifluid sedimentation