Contenu du sommaire

The aim of this paper is to study the impact of demographic ageing on unemployment. According to neokeynesian macroe- conomic models, the influence should be limited and transitory. Teachings of the labour economy are more informative. Firstly, we calibrate a model of equilibrium unemployment and estimate at -0.8 percentage points the impact of ageing on unemployment. Nevertheless, reforms which are proposed to perpetuate public pension systems are likely to affect this result. We evaluate that the unemployment rate could decrease by more than 1 point if the balance of pension systems was exclusively achieved by an extension of the duration of contribution. On the contrary, the unemployment rate could increase by 0.2 points if the balance of pensions was exclusively achieved by an increase in the contribution rate. Secondly, the increase in the share of old workers, who are less likely to be unemployed, could decrease the unemployment rate by more than 0.5 points.

Even though the relationship between saving and demography is clearly established in theory, it is still the subject of controversy at an empirical level. While major demographic changes are developing, we try to investigate the influence of the French population structure on household saving. Our study, which covers the 1970-1997 period, shows that households'saving rate is positively related to the proportion of the 40-59 persons in the population as a whole, and negatively to that of the 75 and more. Those results, corresponding partly to theory, can be put side by side with the available projections of population. We observe that, ceteris paribus, the saving rate should increase until 2005-2010, then decrease because of the baby boom generation then retiring. The population ageing should also imply variations in the allocation of saving, with a preference for long term assets for a few years to come.

In this article we first review empirical results on activity and unemployment of old-age workers that can be found in the economic literature. Then we expose the main labor supply models that have been used to explain retirement behavior. Finally we review economic studies bearing on the analysis of the relations between productivity and wages as well as models describing firm behavior towards old-age workers. In conclusion, we point out some research directions that could be followed to fill the gaps persisting in the economic literature.

This paper examines the impact that reforms of the French welfare system could have on the employment and labour force participation of welfare recipients. More specifically we present predictions of the individuals'labour supply behaviour that could result from the introduction of a few reform scenarios based on a reduction of the marginal implicit income tax rate faced by welfare recipients under the current system. These predictions are derived from a structural modelization and an econometric estimation of the labour supply of single-head households discussed in detail in Gravel-Hagneré-Picard (2000). The fraction of actually unemployed single head households who would become employed after the reforms never exceed 15 % of the total target population. Moreover, some households head who were working under the current system would choose to reduce their hours worked. The aggregate effect of all the reforms on the labour supply turns out to be negative. On the other hand, this kind of reform appears to have an undeniable redis- tributive effect. Among the reforms considered, it is the one associated with a 40 percent implicit marginal tax rate on the labour income which seems to represent the best compromise between equity and efficiency considerations.

Introducing Managed Care in the French Health Care System. Implementing managed care techniques seems highly desirable to improve productive efficiency on health care markets. We describe an abstract regulatory framework featuring « health operators » competing in a fully state-financed system. The competition process does not concern the insurance side (the state provides health insurance for the whole population), but only the characteristics of the health services (each individual freely chooses his operator on a quality basis). The operators receive a risk-adjusted premium for each customer and contract for services with health care providers. We compare this model with current experiments in Europe and the United States. We analyse the tradeoff between efficiency and selection in this context and evaluate regulatory costs of the model.

In this article, we use both theoretical and industrial policy arguments to confront different assignment methods for spectrum licenses. After a brief survey of the history of assignment practices, we compare comparative hearings with auction. Then, we present several auction rules and their properties when each bidder can obtain at most one license. We compare open and sealed-bid, sequential and simultaneous auctions. We point out in each case the sensibility to collusion, the occurence of the winner's curse, the prices convergence and more specific auction rules. We justify the wide use of simultaneous ascending auction. In the last section, we consider multi- unit demand and we compare simple and complex auctions, when bidders can aggregate more than one license.