Job Creation, Job Destruction and the Life Cycle

This paper originally incorporates life-cycle features into the job creation - job destruction framework. Once a finite horizon is introduced, this workhorse labor market model naturally delivers the empirically uncontroversial prediction that the employment rate of workers decreases with age due to lower hirings and higher firings of older workers. This age profile of hirings and firings is in addition found to be optimal in a competitive search equilibrium context. If search externalities are not internalized and unemployment benefits distort equilibrium, there is a room for labor market policy differentiated by age. This lastly allows us to debate the incidence of labor demand policies which have been introduced in many countries to favor the older worker employment. We show that hiring subsidies and firing costs should be decreasing with age when unemployment benefits are sufficiently high, as in the Europe. On the contrary, if unemployment benefits are low, as in the US, optimal hiring subsidies and firing taxes should be increasing with age. In this latter case, the introduction of anti-discrimination laws is a good proxy of this first best policy.Job creations and destructions, Life cycle, Older workers

Returns to firm-provided training in France: Evidence on mobility and wages

Returns to training, matching estimators, labour market mobility, wages, France

Incentive Schemes to Delay Retirement and the Equilibrium Interplay with Human Capital Investment

This article introduces the role of labor demand of the elderly in the analysis of retirement decisions. We integrate both human capital formation and up-dating costs on older workers' job and explore how Social Security system affects human capital investment and retirement decisions. We show that, from the worker''s point of view, human capital investment and retirement age decisions are interdependent and positively related. On the one hand, an actuarially unfair pay-as-you-go system imposes a tax on postponed retirement which encourages early retirement, thus reducing incentives to invest in human capital. On the other hand, the pension system imposes a tax on training intensity. As a result, workers have less incentives to continue working. From the firm''s point of view, this implies an indirect tax on labor demand due to the decrease in older workers'' productivity. We then examine the pattern of the optimal policies according to flexibility versus rigidity of wages.

Voluntary and involuntary retirement decision : does real wage rigidity affects the effectiveness of pension reforms ?

In this paper, we integrate the retirement deadline taking into account both labor demand and labor supply specificities. This approach reveals that firms' employment decisions play an active role in the early retirement decision. We show that, in a walrasian economy, social security reforms aimed at delaying the retirement age by introducing actuarially fair adjustments are particularly powerful to stimulate the employment of older workers. However, if real wages are rigid, two situations must be distinguished. First, if the wage is lower than its walrasian value, the separation date is determined by workers, fair adjustments would push back the retirement age. In contrast, when the wage exceeds its walrasian rate, the separation date is determined by firms. Trying to increase the rate of employment of older workers by introducing pension incentives seems to be an unattainable goal. Therefore, there is a good reason for focusing primarily on labor demand. In this case, it appears that paying a subsidy to firms is the best policy for attaining the optimal retirement age.Retirement age, Human capital investment, Real wage rigidity, Labor market reform

Voluntary and involuntary retirement decision : does real wage rigidity affects the effectiveness of pension reforms ?

In this paper, we integrate the retirement deadline taking into account both labor demand and labor supply specificities. This approach reveals that firms' employment decisions play an active role in the early retirement decision. We show that, in a walrasian economy, social security reforms aimed at delaying the retirement age by introducing actuarially fair adjustments are particularly powerful to stimulate the employment of older workers. However, if real wages are rigid, two situations must be distinguished. First, if the wage is lower than its walrasian value, the separation date is determined by workers, fair adjustments would push back the retirement age. In contrast, when the wage exceeds its walrasian rate, the separation date is determined by firms. Trying to increase the rate of employment of older workers by introducing pension incentives seems to be an unattainable goal. Therefore, there is a good reason for focusing primarily on labor demand. In this case, it appears that paying a subsidy to firms is the best policy for attaining the optimal retirement age

Voluntary and involuntary retirement decision : does real wage rigidity affects the effectiveness of pension reforms ?

In this paper, we integrate the retirement deadline taking into account both labor demand and labor supply specificities. This approach reveals that firms' employment decisions play an active role in the early retirement decision. We show that, in a walrasian economy, social security reforms aimed at delaying the retirement age by introducing actuarially fair adjustments are particularly powerful to stimulate the employment of older workers. However, if real wages are rigid, two situations must be distinguished. First, if the wage is lower than its walrasian value, the separation date is determined by workers, fair adjustments would push back the retirement age. In contrast, when the wage exceeds its walrasian rate, the separation date is determined by firms. Trying to increase the rate of employment of older workers by introducing pension incentives seems to be an unattainable goal. Therefore, there is a good reason for focusing primarily on labor demand. In this case, it appears that paying a subsidy to firms is the best policy for attaining the optimal retirement age

Role of molecular ions in plasmas of atmospheric and energetic interest

Bultel, A Cheron, BG 6th International Conference on Dissociative Recombination Jul 12-16, 2004 Mosbach, GERMANYMolecular ions often play a very important role in plasmas. The electron energy distribution function (eedf) and density (n(e)) are influenced by the reactions of molecular ions with electrons. We bring these aspects into focus by studying successively the following situations: We show that the dissociative recombination of Ar-2(+) allows to understand the measured characteristics of an argon supersonic plasma flow where the electron density is low. Afterwards, we show the dominating role of NO+ in the chemistry of a space vehicle atmospheric re-entry air plasma. Finally, by using the Boltzmann equation in order to show the influence of molecular ions such as NO+ in air plasmas on the eedf, we comment on the common assumption of Maxwell-Boltzmann equilibrium for this distribution

Search frictions and (in)efficient vocational training over the life-cycle

This paper examines life cycle vocational training investments in the context of a model with search frictions. We emphasize that related externalities are agedependent, and this can require an hump-shaped subsidy rate of training costs to restore social efficiency. These results are illustrated using a calibration on the french econom