À la recherche des biens sous tutelle

La notion de biens sous tutelle (merit goods) introduite par Musgrave en 1957 définit des biens pour lesquels l’évaluation sociale ne provient pas uniquement des informations fournies par les préférences individuelles. L’utilisation d’un argument de type biens sous tutelle pour justifier l’intervention de l’État est très fréquente dans le domaine culturel, la santé, la protection de la biodiversité, etc. Pour autant, la légitimité économique de cet argument demeure controversée : qu’est-ce qui peut justifier que l’État s’érige en tuteur des préférences des individus?L’objet de cet article est de clarifier la place occupée par les biens sous tutelle en économie du bien-être. La première partie définit le concept et présente les problèmes qu’il pose à la théorie économique. Par la suite, nous montrons comment certaines extensions de la théorie, en particulier les avancées proposées par l’économie comportementale, contribuent à asseoir sa légitimité économique tant du point de vue des préférences individuelles que du choix social.Musgrave’s so-called merit goods, introduced in 1957, intend to deal with situations where the social weight or concern of a good differs from the information given by individual preferences. Merit goods are often referred to as a case for government intervention in education, health care or biodiversity protection policies. But theoretical roots of this concept seem a bit fuzzy and are, at best, very controversial. To put it crudely, what –if anything– can justify that government choices rule out individual choices? The paper deals with this issue. What role do merit goods play in economic theory?The first part of the paper defines the concept of merit goods and emphasizes the theoretical issues at stake. Afterward, we show how recent developments in economic theory, especially behavorial economics, provide a useful framework for the recognition of the concept, both as for individual decision making theory as for social choice

A la recherche des Merit Goods

Musgrave’s so-called merit goods, introduced in 1957, intend to deal with the situations where the social weight or concern of a good differs from the information given by individual preferences. Merit goods are often referred to as a case for government intervention in education, health care or biodiversity protection policies…. But the theoretical roots of this concept seem a bit fuzzy and are, at best, very controversial. To put it crudely, what –if anything- can justify that government choices rule out individual choices? The paper tries to answer this question. What role do merit goods play in economic theory? The first part of the paper defines the concept of merit good and emphasizes the theoretical issues at stake. The second part studies in what way the concept of merit good can be compatible with economic theory. We show, in particular, how this concept fits well with the development related to individual decision making theory, known as behavioural economics.

Genetic determinism of sensitivity to Corynespora cassiicola exudates in rubber tree (Hevea brasiliensis)

An indirect phenotyping method was developed in order to estimate the susceptibility of rubber tree clonal varieties to Corynespora Leaf Fall (CLF) disease caused by the ascomycete Corynespora cassiicola. This method consists in quantifying the impact of fungal exudates on detached leaves by measuring the induced electrolyte leakage (EL%). The tested exudates were either crude culture filtrates from diverse C. cassiicola isolates or the purified cassiicolin (Cas1), a small secreted effector protein produced by the aggressive isolate CCP. The test was found to be quantitative, with the EL% response proportional to toxin concentration. For eight clones tested with two aggressive isolates, the EL% response to the filtrates positively correlated to the response induced by conidial inoculation. The toxicity test applied to 18 clones using 13 toxinic treatments evidenced an important variability among clones and treatments, with a significant additional clone x treatment interaction effect. A genetic linkage map was built using 306 microsatellite markers, from the F1 population of the PB260 x RRIM600 family. Phenotyping of the population for sensitivity to the purified Cas1 effector and to culture filtrates from seven C. cassiicola isolates revealed a polygenic determinism, with six QTL detected on five chromosomes and percentages of explained phenotypic variance varying from 11 to 17%. Two common QTL were identified for the CCP filtrate and the purified cassiicolin, suggesting that Cas1 may be the main effector of CCP filtrate toxicity. The CCP filtrate clearly contrasted with all other filtrates. The toxicity test based on Electrolyte Leakage Measurement offers the opportunity to assess the sensitivity of rubber genotypes to C. cassiicola exudates or purified effectors for genetic investigations and early selection, without risk of spreading the fungus in plantations. However, the power of this test for predicting field susceptibility of rubber clones to CLF will have to be further investigated. (Résumé d'auteur

The late Holocene record of Lake Mareotis, Nile Delta, Egypt

Lake Maryut (northwestern Nile Delta, Egypt) was a key feature of Alexandria's hinterland and economy during Greco-Roman times. Its shores accommodated major economic centers, and the lake acted as a gateway between the Nile valley and the Mediterranean. It is suggested that lake-level changes, connections with the Nile and the sea, and possible high-energy events considerably shaped the human occupation history of the Maryut. To reconstruct Lake Maryut hydrology in historical times, we used faunal remains, geochemistry (Sr isotopic signature of ostracods) and geoarcheological indicators of relative lake-level changes. The data show both a rise in Nile inputs to the basin during the first millennia BCE and CE and a lake-level rise of ca. 1.5 m during the Roman period. A high-energy deposit, inferred from reworked radiocarbon dates, may explain an enigmatic sedimentary hiatus previously attested to in Maryut's chronostratigraphy