Publications

Abstract From July 25 to 31, 1796, Georg Wilhelm Friedrich Hegel, then working as a private tutor for the aristocracy in Bern, took a mountain hike in the neighbouring Alps. Hegel travelled from Thoune to Altdorg via the Jungfrau and the Uri, a land of glaciers. As Hegel began studying economics for good, the query would reappear: in his reading of Sir James Steuart’s Inquiry into the Principles of Political economy, Hegel would make his first step into economic theorizing. In Frankfurt, Hegel was not yet a tenured Gymnasium professor. He was again a private tutor, experiencing hardships of a salaried life – though in wealthy families. Paul Chamley selected excerpts of interest based on his first assessment of the thesis that there surely exists a solid ‘system of political economy’ by Hegel. He assumed it rather than he found it as a result of his comparative study.
HAL Google Scholar
Abstract The bootstrap is a technique for performing statistical inference. The underlying idea is that most properties of an unknown distribution can be estimated as the same properties of an estimate of that distribution. In most cases, these properties must be estimated by a simulation experiment. The parametric bootstrap can be used when a statistical model is estimated using maximum likelihood since the parameter estimates thus obtained serve to characterise a distribution that can subsequently be used to generate simulated data sets. Simulated test statistics or estimators can then be computed for each of these data sets, and their distribution is an estimate of their distribution under the unknown distribution. The most popular sort of bootstrap is based on resampling the observations of the original data set with replacement in order to constitute simulated data sets, which typically contain some of the original observations more than once, some not at all. A special case of the bootstrap is a Monte Carlo test, whereby the test statistic has the same distribution for all data distributions allowed by the null hypothesis under test. A Monte Carlo test permits exact inference with the probability of Type I error equal to the significance level. More generally, there are two Golden Rules which, when followed, lead to inference that, although not exact, is often a striking improvement on inference based on asymptotic theory. The bootstrap also permits construction of confidence intervals of improved quality. Some techniques are discussed for data that are heteroskedastic, autocorrelated, or clustered.
Publication HAL Google Scholar
Abstract The digital age allows data collection to be done on a large scale and at low cost. This is the case of genealogy trees, which flourish on numerous digital platforms thanks to the collaboration of a mass of individuals wishing to trace their origins and share them with other users. The family trees constituted in this way contain information on the links between individuals and their ancestors, which can be used in historical demography, and more particularly to study migration phenomena. The case of 19th century France is taken as an example, using data from the family trees of 238,009 users of the Geneanet website, or 2.5 million (unique) individuals. Using the geographical coordinates of the birthplaces of 25,485 ancestors born in France between 1800 and 1804 and those of their descendants (24,516 children, 29,715 grandchildren and 62,165 great-grandchildren), we study migration between generations at several geographical scales. We start with a broad scale that of the departments, to reach a much finer one, that of the cities. Our results are consistent with those of the literature traditionally based on the parish or civil status registers. The results show that the use of collaborative genealogy data not only makes it possible to support previous findings of the literature, but also to enrich them.
Keywords 19th Century, Migration, Collaborative data, Genealogy
Publication HAL Google Scholar
Abstract Intermediary organisations have increasingly played a role in payments for agri-environment services across Europe over the last two decades. However, the economics literature has so far not examined the impact of this new governance mechanism on environmental protection and on individuals' behaviour. We develop a new theoretical economic framework to compare an incentive mechanism using intermediaries, such as environmental knowledge brokers and information providers, with a standard central governance mechanism, in terms of environmental impact. We show that the emergence of knowledge intermediaries is particularly effective where farmers initially have low environmental awareness, or when the public institution organizing the scheme is insufficiently aware of individuals' characteristics. Our findings provide theoretical support for previous empirical results on payment schemes for agri-environment measures.
Keywords Principal-agent, Cultural transmission, Agri-environment measures, Pro-environmental culture, Non-profit organisations, Intermediaries, Knowledge brokers
Publication HAL Google Scholar
Abstract In this paper, we investigate the effects of trade in foods on obesity in Mexico. To do so, we match data on Mexican food imports from the U.S. with anthropometric and food expenditure data. Our findings suggest that exposure to food imports from the U.S. can explain up to 20% of the rise in obesity prevalence among Mexican women between 1988 and 2012. Pro-obesity effects are driven by areas more exposed to unhealthy food imports. We also find evidence in favour of a price mechanism. By linking trade flows to obesity, the paper sheds light on an important channel through which globalisation may affect health. (C) 2019 Elsevier B.V. All rights reserved.
Keywords Trade Obesity Nutrition transition Mexico
Publication HAL Google Scholar