Showing papers by "Paris West University Nanterre La Défense published in 2003"

Adverse selection and moral hazard in insurance: Can dynamic data help to distinguish?

Abstract: A standard problem of applied contracts theory is to empirically distinguish between adverse selection and moral hazard. We show that dynamic insurance data allow to distinguish moral hazard from dynamic selection on unobservables. In the presence of moral hazard, experience rating implies negative occurrence dependence: individual claim intensities decrease with the number of past claims. We discuss econometric tests for the various types of data that are typically available. Finally, we argue that dynamic data also allow to test for adverse selection, even if it is based on asymmetric learning. (JEL: D82, G22, C41, C14)

Fixed fees and physician-induced demand: a panel data study on French physicians.

Abstract: This paper investigates on the existence of physician-induced demand (PID) for French physicians. The test is carried out for GPs and specialists, using a representative sample of 4500 French self-employed physicians over the 1979-1993 period. These physicians receive a fee-for-services (FFS) payment and fees are controlled. The panel structure of our data allows us to take into account unobserved heterogeneity related to the characteristics of physicians and their patients. We use generalized method of moments (GMM) estimators in order to obtain consistent and efficient estimates. We show that physicians experience a decline of the number of consultations when they face an increase in the physician:population ratio. However this decrease is very slight. In addition, physicians counterbalance the fall in the number of consultations by an increase in the volume of care delivered in each encounter. Econometric results give a strong support for the existence of PID in the French system for ambulatory care.

Forecasting Inflation Using Economic Indicators: The Case of France

Abstract: In order to provide short run forecasts of headline and core HICP inflation for France, we assess the forecasting performance of a large set of economic indicators, individually and jointly, as well as using dynamic factor models. We run out-of-sample forecasts implementing the Stock and Watson (1999) methodology. It turns out that, according to usual statistical criteria, the combination of several indicators - in particular those derived from surveys- provides better results than dynamic factor models, even after pre-selection of the variables included in the panel. However, factors included in VAR models exhibit more stable forecasting performance over time. Results for HICP excluding unprocessed food and energy are very encouraging. Moreover, we show that it is possible to use forecasts on this indicator to project overall inflation.

Forecasting Inflation in the Euro Area

Abstract: In order to provide medium run forecasts of headline and core HICP inflation for the euro area, we assess the usefulness of dynamic factor models. We use Stock and Watson's (1999) out-of-sample methodology for models estimated over the 1988:1-2002:3 period, with balanced and unbalanced panels. We provide evidence that factors alone or combined with indicators help improve upon the simple Autoregressive (AR) model for forecasting HICP core inflation as well total inflation, if one refers to the usual criterion of "Relative MSE" together with its standard deviation. However, regarding total HICP we do not produce forecasts that are totally satisfactory in the sense of being capable of recognizing the 1999-2000 upturn in inflation in a timely manner. But, from that point of view, the construction of a ''synthetic core'' indicator helps achieve significantly better forecasts over a 12-month horizon than the AR model for total inflation for the final part of the sample. We also show that the results are rather robust to potential data-snooping.

Moral hazard and dynamic insurance data

Abstract: This paper exploits dynamic features of insurance contracts in the empirical analysis of moral hazard. We first show that experience rating implies negative occurrence dependence under moral hazard: individual claim intensities decrease with the number of past claims. We then show that dynamic insurance data allow to distinguish this moral-hazard effect from dynamic selection on unobservables. We develop nonparametric tests and estimate a flexible parametric model. We find no evidence of moral hazard in French car insurance. Our analysis contributes to a recent literature based on static data that has problems distinguishing between moral hazard and selection and dealing with dynamic features of actual insurance contracts. Methodologically, this paper builds on and extends the literature on state dependence and heterogeneity in event-history data. (JEL: D82, G22, C41, C14)

Bonus-malus scales in segmented tariffs with stochastic migration between segments

Abstract: This article proposes a computer-intensive methodology to build bonus-malus scales in automobile insurance. The claim frequency model is taken from Pinquet, Guillen, and Bolance (2001). It accounts for overdispersion, heteroskedasticity, and dependence among repeated observations. Explanatory variables are taken into account in the determination of the relativities, yielding an integrated automobile ratemaking scheme. In that respect, it complements the study of Taylor (1997).

The Emergence and Uncertain Outcomes of Prostitutes' Social Movements:

Abstract: This article is a comparative study of five prostitutes' social movements. The emergence of these movements is one of the major developments in the politics of prostitution: for the first time, prostitutes are politically organizing and expressing their claims and grievances in the public debate about prostitution — a debate from which they are usually excluded. But, as is the case for most stigmatized populations, this pretension to enter into the public debate is faced with many difficulties. Some of these are inherent to the world of prostitution, which is an informal, competitive and violent world, in which leaders face constant challenges to establish and maintain their authority and legitimacy. The article also emphasizes the crucial, but ambiguous, role played by alliances between prostitutes and people from other parts of society (especially feminists). Prostitutes' dependence on these supporters leads the author to consider their social movements to be heteronomous mobilizations.

Optimal Area-Yield Crop Insurance Reconsidered

Abstract: The implementability of area-yield insurance contracts in the presence of symmetric and asymmetric information about the farmer's “beta” linking his yield to the risk-pool's yield is examined. In the presence of fixed costs and symmetric information Mahul's result that optimality requires setting the slope of the indemnity schedule equal to each farmer's beta is confirmed. When there is asymmetric information between the insurer and the farmer, however, this full-insurance contract is vulnerable to adverse selection, and therefore may not be implementable for general cost structures. The optimal area-yield insurance contract under asymmetric information is characterized.

La double dimension de l'apprentissage autodirigé Contribution à une théorie du sujet social apprenant

Abstract: In this article the author lays the foundation for a conceptualization of self-direction from an analysis of its place in the debates occurring in both Europe and North America. The proposed model is grounded in two meanings of the concept: the self-determined will to learn and the abilities of learning self-regulation. Self-efficacy to learn underlies these two meanings in the proposed conceptualization of self-direction. Resume Cet article jette les bases d'une conceptualisation de l'autodirection a partir du debat sur cette notion en Amerique du Nord et en Europe. Le modele theorique propose est enracine dans deux dimensions conceptuelles : la volonte autodeterminee d'apprendre d'un cote et les capacites d'autoregulation de l'apprentissage de l'autre. Le sentiment d'efficacite personnelle a apprendre est sous-jacent a ces deux dimensions dans le modele propose de l'autodirection.

De la scolarisation de masse à la formation tout au long de la vie : essai sur les enjeux économiques des doctrines éducatives des organisations internationales

Abstract: De la planification centralisee de l’offre scolaire en fonction des besoins de main-d’œuvre au “lifelong learning” pilote par la demande, les doctrines educatives des organisations internationales ont fluctue depuis un demi-siecle. L’objet de cet article est de reperer les changements d’enjeux economiques qui peuvent contribuer a expliquer cette evolution. On peut distinguer sur cette periode trois phases dans les rapports qu’entretient le regime d’accumulation avec ses besoins qualitatifs en main-d’œuvre, dont la traduction doctrinale peut etre synthetisee par trois metaphores successives: “industrielle” jusqu’a la fin des annees 1960, “sportive” dans les annees 1970, “boursiere” depuis les annees 1980. Ce qui devrait permettre de remettre en perspective aussi bien les naturalisations actuelles de l’acquisition des savoirs comme placement financier et de l’enseignement comme service banalise que la substitution du management de l’education a sa politique.

Could short selling make financial markets tumble

Abstract: It is suggested to consider long term trends of financial markets as a growth phenomenon. The question that is asked is what conditions are needed for a long term sustainable growth or contraction in a financial market? The paper discuss the role of traditional market players of long only mutual funds versus hedge funds which take both short and long positions. It will be argued that financial markets since their very origin and only till very recently, have been in a state of ``broken symmetry'' which favored long term growth instead of contraction. The reason for this ``broken symmetry'' into a long term ``bull phase'' is the historical almost complete dominance by long only players in financial markets. Dangers connected to short trading are illustrated by the appearence of long term bearish trends seen in analytical results and by simulation results of an agent based market model. Recent short trade data of the Nasdaq Composite index show an increase in the short activity prior to or at the same time as dips in the market, and reveal an steadily increase in the short trading activity, reaching levels never seen before.

The Liberating Role of Conflict in Group Creativity: A Cross Cultural Study

Abstract: Researchers of group creativity have noted problems such as social loafing, "production blocking," and especially, evaluation apprehension (Paulus, 2000). Thus, brainstorming techniques have specifically admonished people "not to criticize" their own and others' ideas, a tenet that has gone unexamined. In contrast, there is research showing that dissent, debate and competing views have positive value, stimulating divergent and creative thought (Nemeth, 2002, in press). In this experimental study, traditional brainstorming instructions admonishing people not to criticize were compared with instructions encouraging people to debate and even criticize. A third condition offered no specific instructions. This study was conducted both in the United States and in France. Results show the value of both types of instructions, but, in general, debate instructions were superior to traditional brainstorming instructions. Further, these findings hold across both cultures. Results are discussed in terms of the positive value of encouraging debate and controversy for idea generation.

Replicant compression coding in Besov spaces

Abstract: We present here a new proof of the theorem of Birman and Solomyak on the metric entropy of the unit ball of a Besov space on a regular domain of The result is: if s - d(1/π - 1/p) + > 0, then the Kolmogorov metric entropy satisfies H(e) ~ e -d/s . This proof takes advantage of the representation of such spaces on wavelet type bases and extends the result to more general spaces. The lower bound is a consequence of very simple probabilistic exponential inequalities. To prove the upper bound, we provide a new universal coding based on a thresholding-quantizing procedure using replication.

Electronic government and the French state: A negotiated and gradual reform

Abstract: In France, electronic administration has become an emblem of State and Civil service modernization. For a better understanding of the way in which Information Technology (IT) has gradually become part of the somewhat traditional effort at French State modernization, this paper will analyse the processes involved in the construction of a complete and coherent project. The in-depth study of public reports and interviews carried out with main actors involved in the reform shows the hazards of the process. Revealing the ways and means in which IT has an influence on modernization enhances understanding of the nature of the changes sought. This paper provides an opportunity to take into account the players' viewpoints, starting with unresolved issues and the tensions resulting from the reforms. The final part of the paper focuses on the so-called Bercy reforms.

How to regulate heterogenous hospitals

Abstract: Ways to regulate French public hospitals? The purpose of this paper is to study hospital costs in the event of introduction of a Prospective Payment System in France. We use a nested three dimensional database (stays-hospitals-years) in order to identify hospital unobservable heterogeneity and a transitory moral hazard component of cost variability. Econometric estimate are performed on a sample of 7,314 stays for acute myocardial infarction observed in 36 French public hospitals over the period 1994 to 1997. Transitory moral hazard is far from negligible : its estimated standard error is about 50 % of the standard error we estimate for cost variability due to permanent unobervable heterogeneity between hospitals. Simulations show that a cost reduction of about 16 % can be expected from implmentation of a payment system which allows for permanent unobserved heterogeneity and eliminates only transitory moral hazard.

Excess Returns, Portfolio Choices and Exchange Rate Dynamics: The Yen/Dollar Case, 1980-1998

Abstract: We built a portfolio choice model in which agents are heterogeneous and possibly draw systematic rational forecast errors.(This abstract was borrowed from another version of this item.)(This abstract was borrowed from another version of this item.)

Quand les morts reviennent, réflexion sur l'ancestralité chez les Mayas des Basses Terres

Abstract: Quand les morts reviennent… Reflexion sur l’ancestralite chez les Mayas des Basses Terres. Le culte des ancetres est souvent evoque dans la litterature ethnologique amerindienne, sans que soit pourtant etablie son existence. Cet article s’attache a montrer que certains groupes mayas des Basses Terres pratiquent un culte familial des ancetres, dont le jour des morts, ou hanal pixan, apparait comme la manifestation la plus pregnante. Nous fonderons notre raisonnement sur des criteres precis empruntes a des etudes ethnologiques de societes dites « a ancetres » auxquels seront confrontees les croyances et les pratiques mayas. L’approche est comparative, a la fois dans le temps, en croisant des donnees coloniales et ethnographiques du xxe siecle, et dans l’espace, en confrontant les usages et les croyances de deux groupes mayas pourtant apparentes, les Yucateques et les Lacandons.

Nominal and Real Convergence in Estonia: The Balassa-Samuelson (dis)connection

Abstract: The objective of the paper is to analyse the nominal and real convergence process in Estonia drawing on the Balassa-Samuelson (B-S) framework. A 15-sectoral breakdown for GDP and a 5-digit level CPI data disaggregation with over 260 items is used for the period 1993:Q1 to 2002:Q1 to show that the productivity differential is related to the GDP-deflator relative price of non-tradable goods in the long run. Furthermore, the role of regulated prices in the CPI basket is also investigated - we show that excluding regulated prices makes it possible to detect a robust relationship between productivity and the relative price of market services in CPI. The B-S effect could have possibly contributed to CPI by a yearly average of 2-3% over the sample period, and more specifically 1-4% at the beginning of the period and 0.5-1% in 2000 and 2001. The potential long-run impact of the B-S effect in Estonia is estimated to amount to 1-2%. Analysis of the influence of the B-S effect on the inflation differential and the real appreciation of the exchange rate against Finland, Sweden, Germany and the UK, shows that, whereas the inflation differential attributable to the B-S effect seems to have been higher in the early 1990s, it better explains the real appreciation occurring in recent years.

Naissance sur l'échafaud : ou la tragédie du début du XVIIe siècle

Abstract: La naissance du theâtre francais, et particulierement de la tragedie francaise, date des dernieres annees du XVIe siecle et des vingt premieres annees du XVIIe, au moment ou emerge ce qu’on peut appeler la « modernite ». Maintenant oublie, et recouvert par le mythe du classicisme francais, ce « theâtre de l’echafaud » s’apparente au theâtre elisabethain et a la comedia espagnole, aussi bien pour son esthetique generale que pour sa maniere de representer le sang, les crimes et les viols, par des actions spectaculaires. Les exemples d’Alexandre Hardy et de Nicolas-Chrestien des Croix, montrent ainsi que cette nouvelle tragedie entend mettre en scene des actions tragiques (sanglantes) en meme temps qu’elle pose a un nouveau public et dans de nouveaux lieux, des questions philosophiques, politiques et religieuses, soulevees par les faits sanglants du temps, par les troubles qui ont saisi la France et par les recentes horreurs des guerres de Religion dont le public a necessairement le souvenir. La loi, l’ordre, la nature humaine, la souverainete, la legitimite, le Salut, sont les grands sujets dont la scene s’empare. Ce faisant, elle oblige les spectateurs a les voir, a en etre saisis, mais aussi a les penser. Car si le theâtre veut interesser son public, il doit le faire d’une part grâce a la representation de transgressions et de contradictions en acte, d’autre part en placant l’assemblee des spectateurs face a des corps souffrants et dans une position ou chacun devient une sorte de juge : un juge impuissant mais implique. La naissance de la modernite et la naissance du theâtre moderne apparaissent donc simultanement en Europe et celebrent l’invention d’une nouvelle distance critique.

Smoking or trading ? On cigarette money in post WW2 Germany

Abstract: Just after world war II, the German money at that time - the Reichsmark - was refused in about 50% of the transactions of consumer goods and had been replaced by barter or commodity moneys such as cigarette. Surprisingly, this episode which is often mentioned (e.g. Friedman 1951, Klein, 1976) has never been studied extensively. Using german and US historical records, this paper built 1/ the history of this cigarette money episode and 2/ a model explaining the use of this commodity money. As we indicate, the appropriate framework for this case is the search-theoretic approach to monetary economics. Our model — with heterogeneous population, mainly smokers and nonsmokers — indicates that the use of cigarette as money depends 1/ on the relative utility of smoking relative to the consumption of other goods and 2/ on the importance of the prior demand for this good, i.e. the proportion of smokers in the population.

Les constructions infinitives dans les grammaires d'arbres polychromes hiérarchisées

Abstract: Dans cet article, nous proposons une analyse syntaxique des constructions infinitives (ou infinitives) en francais. Pour nous, suivant en cela Huot (1981) et Baschung (1991), une construction infinitive est le groupe forme par un verbe infinitif et son environnement. Cette definition est plus large que celle de Grevisse (1964) et Lorian (1962), et que celle proposee plus recemment par Legrand (1999) et Leeman (2002). Les premiers considerent que l'on peut parler de proposition infinitive quan...

Changing Definitions of Risk and Responsibility in French Political Scandals

Abstract: In the 1990s in France, a large number of political scandals developed and many political actors were prosecuted. This process of making politicians responsible related, in particular, to the rise of "new risks" regarding public health and security. In this paper, I analyse the diffusion and the crystallization of discourses linking public risk and political responsibility. First, I point to some of the social and cognitive bases in which the recent uses of the notions of risk and responsibility are rooted. Second, I focus on the mechanisms through which the notions were mobilized and invested with new definitions in the course of the scandal hearings. Third, I explore some of the effects of the changes which occurred during the 1990s: new perception frames in terms of risk and responsibility are consolidated and are progressively appropriated by social actors located in various professional spheres.

Sustainable management of an exhaustible resource:a viable control model

Abstract: We examine sustainability conditions of an economic production-consumption system based on the use of an exhaustible natural resource. But instead of studying the environmental and economic interactions in terms of optimal control, we pay much attention to the viability of the system. The ex ante viability, defined by a set of constraints combining a guaranteed consumption and a stock of resource to preserve at any time, refers to a Rawlsian intergenerational equity perspective. Using the mathematical concept of viability kernel dealing with the consistency between the constraints and the controlled dynamics, we reveal the sustainable technological configurations and, whenever possible, policies options and environmental-economic states to guarantee a perennial system. We point out the flexibility in “extractionconsumption” choices. Numerical simulations illustrate the general results. Key-words: Exhaustible resource, Sustainability, Viability kernel. JEL Classification: Q01, Q32, O13, C61. ∗THEMA (THeorie Economique, Modelisation et Applications). Universite Paris X-Nanterre, 200 Av. de la Republique, 92001 Nanterre Cedex, France. Email: vincent.martinet@u-paris10.fr †CNRS, CIRED (Centre International de Recherche pour l’Environnement et le Developpement), Campus Jardin Tropical de Paris, 45bis Avenue de la Belle Gabrielle, 94736 Nogent sur Marne, France. Email: doyen@centre-cired.fr

Frequency-domain estimation of fractionally integrated processes: impact of short-term components on the bandwidth

Abstract: The purpose of this paper is to evaluate the impact of the bandwidth on the estimate of the fractional differencing parameter d for two frequency-domain estimation procedures: the Geweke and Porter-Hudak (1983) method and the Lobato and Robinson (1998) test. A Monte Carlo study is implemented on two processes: a pure fractionally integrated process and an ARFIMA(1, d, 0) process in order to study the influence of short-term components on the optimal bandwidth. Our results indicate that the two procedures are very sensitive both to the bandwidth, and to the presence of short-term components. In order to avoid these problems, a graphical method is suggested for estimating ARFIMA processes. It performs especially well for high values of short-term components, avoiding the dramatic bias of the previous estimates.