Pierre-Yves Geoffard

Moral Hazard and the Demand for Physician Services: First Lessons from a French Natural Experiment

This paper presents first empirical results on moral hazard in demand for physician services, using a longitudinal dataset on 4578 individuals followed during two years. The data set contains two subgroups, one for which a copayment rate of 10% for physician visits was introduced in 1994, and an other for which no change occured during the period of the study. This enables us to use these data as coming from a controlled natural experiment. We test if the number of visits per agent was modified by this copayment rate. The data reject the hypothesis for office visits, but do not for home visits. This suggests that there is moral hazard in demand for some physician services, but also that when non-monetary costs are important, small changes in monetary price may not induce any major change in behaviour.

Rational Epidemics and Their Public Control

This paper studies an economic model of the dynamic spread of an infectious disease, contrasting its implications in terms of the occurrence of the disease itself, as well as the effects of public health interventions, with those of mathematical epidemiology. Copyright 1996 by Economics Department of the University of Pennsylvania and the Osaka University Institute of Social and Economic Research Association.

Sunspot Fluctuations around a Steady State: The Case of Multidimensional, One-Step Forward Looking Economic Models

The paper investigates the existence of stationary sunspot equilibria (SSE) in the vicinity of a steady state in a general, one-step forward looking economic model of dimension n. It is shown that, whenever the steady state is indeterminate, for the associated deterministic dynamics--i.e., there exists a continuum of perfect foresight paths converging to the steady state--then there exists a continuum of SSE of finite order in any neighborhood of the steady state. The proof relies upon bifurcation theory; it provides a characterization of the random processes for which SSE may appear and a description of the location of the support of the SSE close to the bifurcation. The results apply in particular to linear models. Copyright 1992 by The Econometric Society.

Family income and child health in the UK

Recent studies examining the relationship between family income and child health in the UK have produced mixed findings. We re-examine the income gradient in child general health and its evolution with child age in this country, using a very large sample of British children. We find that there is no correlation between income and child general health at ages 0-1, that the gradient emerges around age 2 and is constant from age 2 to age 17. In addition, we show that the gradient remains large and significant when we reduce the endogeneity of income. Furthermore, our results indicate that the gradient in general health reflects a greater prevalence of chronic conditions among low-income children and a greater severity of these conditions. Taken together, these findings suggest that income does matter for child health in the UK and may play a role in the intergenerational transmission of socioeconomic status.

Reforming Incentive Schemes Under Political Constraints: The Physician Agency

In many developed countries attempts to reform physicians payment schemes have failed. To analyze some of the difficulties, this paper studies reforms of payment schemes in situations such as the physician agency, where the quality of the good produced is imperfectly observable by the payer. We first study the situation, common in many countries, where physicians face a single scheme. We identify conditions under which no reform can both obtain the consent of a large proportion of physicians (political constraints) and improve patients welfare. We then study whether a menu of contracts, with or without cross subsidies, may solve the difficulties generated by the heterogeneity of producers practice.

Changing time and emotions

In this paper, we consider that our experience of time (to come) depends on the emotions we feel when we imagine future pleasant or unpleasant events. A positive emotion such as relief or joy associated with a pleasant event that will happen in the future induces impatience. Impatience, in our context, implies that the experience of time up to the forthcoming event expands. A negative emotion such as grief or frustration associated with an unpleasant event that will happen in the future triggers anxiety. This will give the experience of time contraction. Time, therefore, is not exogeneously given to the individual and emotions, which link together events or situations, are a constitutive ingredient of the experience of time. Our theory can explain experimental evidence that people tend to prefer to perform painful actions earlier than pleasurable ones, contrary to the predictions yielded by the standard exponential discounting framework.

Pricing and R&D When Consumption Affects Longevity

We analyze goods for which the amount of consumption determines the duration of consumption, focusing on health-related consumption that affects longevity. The characteristics of the demand for such goods lead to unique predictions about private pricing and investment in R&D as well as the fiscal effects of public subsidies and taxes. In particular, we argue that there is an R&D feedback for such goods when the market size expands through longevity-induced population growth. We also argue that as developed countries devote large shares of public spending to old-age programs that may themselves affect longevity, e.g., Medicare and Social Security, the nonstandard effects that these programs introduce may become increasingly important.

Economic and public health consequences of delayed access to medical care for migrants living with HIV in France

In 2013, migrants accounted for 46% of newly diagnosed cases of HIV (human immunodeficiency virus) infection in France. These populations meet with specific obstacles leading to late diagnosis and access to medical care. Delayed access to care (ATC) for HIV-infected migrants reduces their life expectancy and quality of life. Given the reduction of infectivity under antiretroviral (ARV) treatment, delayed ATC for HIV-infected migrants may also hinder the control of the HIV epidemic. The objective of this study is to measure the public health and economic consequences of delayed ATC for migrants living with HIV in France. Using a healthcare payer perspective, our model compares the lifetime averted infections and costs of early vs. late ATC for migrants living with HIV in France. Early and late ATC are defined by an entry into care with a CD4 cell count of 350 and 100/mm3, respectively. Our results show that an early ATC is dominant, even in the worst-case scenario. In the most favorable scenario, early ATC generates an average net saving of €198,000 per patient, and prevents 0.542 secondary infection. In the worst-case scenario, early ATC generates an average net saving of €32,000 per patient, and prevents 0.299 secondary infection. These results are robust to various adverse changes in key parameters and to a definition of late ATC as an access to care at a CD4 level of 200/mm3. In addition to individual health benefits, improving ATC for migrants living with HIV proves efficient in terms of public health and economics. These results stress the benefit of ensuring early ATC for all individuals living with HIV in France.

Child Health and Use of Health Care Services in France: Evidence on the Role of Family Income

Our paper investigates the relationship between family income and child health in France. We first examine whether there is a significant correlation between family income and child general health, and the evolution of this relationship across childhood years. We then study the role of specific health problems, the use of health care services, and supplemental health insurance coverage, in the income gradient in general health. We also quantify the role of income in child anthropometric measurements. Whenever possible, we compare our results for France with those obtained for other developed countries.