Publications

Résumé This paper features a growth model with an appropriative contest and a common-pool investment game between politically organised rival ethnic factions. I determine how the long-run equilibrium coalition shapes incentives to invest, show the existence of a unique steady state, and investigate how the ease to capture rents affects economic performance. The use of numerical simulations concerning a global sample of countries demonstrates that contest intensity can sometimes be beneficial, despite wasteful grabbing behaviours, due to a mechanism related to the concentration of power. When rents become easier to capture, dominant groups have an incentive to expand their influence further. This adjustment can be beneficial as these groups contribute most to capital accumulation.
Mots clés Ethnic, Appropriative competition, Economic performance
Publication HAL Google Scholar
Résumé On a French firm dataset, productivity at the technological frontier has not decelerated and convergence of firms’ productivity has not slowed down. Yet, the dispersion of productivity has increased, which suggests growing difficulties in reallocating production factors between firms.
Publication HAL Google Scholar
Résumé Selon l'auteur, professeur d'économie à l'Université d'Aix-Marseille, le statut des pauvres a évolué. Longtemps oubliés du capitalisme, ils seraient devenus des piliers du profit marchand. De cette relation entre deux entités contradictoires émerge un questionnement sur les fondements et l'avenir du système économique capitaliste. ©Electre 2018
HAL Google Scholar
Résumé Under uncertainty, mean growth of, say, wealth is often defined as the growth rate of average wealth, but it can alternatively be defined as the average growth rate of wealth. We argue that stochastic stability points to the latter notion of mean growth as the theoretically relevant one. Our discussion is cast within the class of continuous-time AK-type models subject to geometric Brownian motions. First, stability concepts related to stochastic linear homogeneous differential equations are introduced and applied to the canonical AK model. It is readily shown that exponential balanced-growth paths are not robust to uncertainty. In a second application, we evaluate the quantitative implications of adopting the stochastic-stability-related concept of mean growth for the comparative statics of global diversification in the seminal model due to Obstfeld (1994).
Mots clés Mean growth, Global diversification, Stochastic stability, Endogenous stochastic growth, AK model
Publication HAL Google Scholar
Résumé We investigate the extent to which standard one sector RBC models with positive externalities and variable capacity utilization can account for the large hump-shaped response of output when the model is submitted to a pure sunspot shock. We refine the Benhabib and Wen (2004) model considering a general type of additive separable preferences and a general production function. We provide a detailed theoretical analysis of local stabilities and local bifurcations as a function of various structural parameters. We show that, when labor is infinitely elastic, local indeterminacy occurs through Flip and Hopf bifurcations for a large set of values for the elasticity of intertemporal substitution in consumption, the degree of increasing returns to scale and the elasticity of capital-labor substitution. Finally, we provide a detailed quantitative assessment of the model and conclude with mixed results. We show that although the model is able theoretically to generate a hump-shaped dynamics of output following an i.i.d. sunspot shock under realistic parameter values, the hump is too persistent for the model to be considered fully satisfactory from an empirical point of view.
Publication HAL Google Scholar
Résumé Developments in macro-econometrics have been evolving since the aftermath of the Second World War. Essentially, macro-econometrics benefited from the development of mathematical, statistical, and econometric tools. Such a research programme has attained a meaningful success as the methods of macro-econometrics have been used widely over about half a century now to check the implications of economic theories, to model macroeconomic relationships, to forecast business cycles, and to helppolicymakers to make appropriate decisions.[...]
Publication HAL Google Scholar
Résumé Biological invasions entail massive biodiversity losses and tremendouseconomic impacts that justify significant management efforts. Because thefunds available to control biological invasions are limited, there is a need toidentify priority species. This paper first review current invasive species pri-oritization methods and explicitly highlights their pitfalls. We then constructa cost-benefit optimization framework that incorporates species utility, eco-logical value, distinctiveness, and species interactions. This framework offersthe theoretical foundations of a simple and operational method for the man-agement of invasive species under a limited budget constraint. It takes theform of an algorithm for the prioritization of multiple biological invasions.
Mots clés Cost/benefit, Prioritization, Biodiversity, Biological invasions, Economic model, Optimization, Conservation des espèces, Biodiversité, Choix d&#039, espèce, Espèce invasive, Modèle économique
Publication HAL Google Scholar
Résumé In this paper, we report the results of risk attitudes elicitation of a French general practitioners national representative sample (N=1568).
Mots clés Risk attitudes, GP&#039, s behavior, Patient-regarding preferences, Representative sample, Medical decision making
Publication HAL Google Scholar
Résumé To expedite payments, firms use convenience pricing strategies. A price is considered convenient if it can be paid with few coins. Convenient prices are well understood in offline retailing, but not online. This article fills the gap, examining an original panel dataset more than 2.5 million observations of book prices from Amazon.com. We provide empirical evidence supporting two claims. First in a static setup, more convenient prices are more likely to be set. Second in a dynamic setup, more convenient prices are more rigid. Emphasizing the role of convenience, this work sheds new light on price setting in online retailing.
Mots clés Convenient prices Price rigidity Rational inattention Amazoncom Online retailing
Publication HAL Google Scholar
Résumé The father of the “Austrian” Marginalist revolution and founder of the so-called “Austrian School of economics”, Carl Menger, had a mixed reception during different periods of development of French economics. Somewhat welcomed in the early days, he was rather forgotten later on. Even his major works were not published in translation until recently. What is the reason for such a situation? Criticisms of classical political economy have to be understood in their French context. In comparison to other countries, this paper details the case of France, besides showing how later Austrians, such as Friedrich Hayek, found a limited audience. This comparative study of economic ideas in France must start with the reception of the views of the founder and the role and impact of adopting/adapting or rejecting his views by French scholars. What place did they find in French academia? From Carl Menger to a “Frenchified” Charles Menger, how was Austrian economic thought disseminated in France? This essay starts by recalling the Belle-Époque and an astonishing letter by Charles Rist for the Jubiläum of Menger, in which he deplored the lack of translation of the latter’s works. The Austrian School in France is then discussed as pure economics replaces political economy in the Interwar period, with the 1938 Paris Congress of “liberal thinkers,” as the Vienna Circle became known, also comparing issues in philosophy. The paper considers how Austrian theories of “pure science” were received in Paris from the Vienna of the 1900s, at a time of ”Crossroads,” to the present day, through the Postwar and Cold War, until a revival since the 1990s and a rethinking of economic ideas after 2008.
Mots clés Transfer of theories in the social sciences, Productive reception, Simiand François, Menger Carl, Hayek Friedrich, Ustrian School of Economics
Publication HAL Google Scholar
Résumé In a similar way to the stock market, the housing market in China has often been portrayed as highly speculative, giving rise to “bubble” concerns. Over the last decade, residential prices increased every year on average by double digits in Beijing or Shanghai. However many observers and researchers argue that fundamentals of the housing sector, both sector-specific and macroeconomic, may have been the driving force behind housing price volatility. While existing empirical work exclusively relies on the government housing prices which may suffer from the well-documented downward bias, this paper uses original high frequency unit price as well as transaction series for the residential resale housing markets of Beijing and Shanghai between January 2005 and December 2010 to test alternative hypotheses about housing prices volatility.
Mots clés MIDAS, Conditional variance, Bubbles, China, Housing prices
Publication HAL Google Scholar
Résumé A general way to study the extremes of a random variable is to consider the family of its Wang distortion risk measures. This class of risk measures encompasses several popular indicators such as the classical quantile/Value-at-Risk, the Tail-Value-at-Risk and the recently introduced Conditional Tail Moments, among others. A couple of very recent studies have focused on the estimation of extreme analogues of such quantities. In this paper, we consider trimmed and winsorised versions of the empirical counterparts of extreme Wang distortion risk measures. We analyse their asymptotic properties, and we show that we can construct bias-corrected trimmed or winsorised estimators of extreme Wang distortion risk measures who appear to perform overall better than their standard empirical counterparts in practice when the underlying distribution has a very heavy right tail. We also showcase our technique on a set of real fire insurance data.
Mots clés Heavy-Tailed Distribution, Extreme value statistics, Asymptotic Normality, Wang distortion risk measure, Trimming, Winsorising
HAL Google Scholar
Résumé We introduce and examine an inexact multi-objective proximal method with a proximal distance as the perturbation term. Our algorithm utilizes a local search descent process that eventually reaches a weak Pareto optimum of a multi-objective function, whose components are the maxima of continuously differentiable functions. Our algorithm gives a new formulation and resolution of the following important distributive justice problem in the context of group dynamics: In each period, if a group creates a cake, the problem is, for each member, to get a high enough share of this cake; if this is not possible, then it is better to quit, breaking the stability of the group.
Publication HAL Google Scholar
Résumé This paper shows the uneven role played in the inflation dynamics of African franc zone countries by their integration in a regional monetary union. We obtain three main results sharply contrasting the central- (CEMAC) and west-African (WAEMU) regions. First, differences in the structure of economies and national fiscal stances play a similar role in both unions and appear as potential sources of inflation differentials. Second, even though co-movements are the principal drivers of inflation dynamics in both subregions, global factors dominate regional ones in WAEMU while both play an equal role in CEMAC. Thirdly, spatial interactions are unimportant in CEMAC due to little intra-zone trade, but take an asymmetric form in WAEMU due to the large size of Ivory Coast and Senegal.
Mots clés Inflation, Common factor models, Spatial dependence, Franc-zone
Publication HAL Google Scholar
Résumé In this paper, we study how rents are shared between capital and labour, using industry†level panel data for 19 OECD countries from 1988 through to 2007. The first step is an explanation of the rent†creation process. We provide evidence of a significant impact of regulation on value†added prices at the industry level relative to the value†added price for the overall economy (rent). In the second step, we dissect the value†added sharing process. By running ordinary least†squares and instrumental variables estimations, we obtain results that confirm the Blanchard–Giavazzi prediction: the impact of rents on the capital share depends on workers' bargaining power.
Mots clés Capital share, Market regulations, Output gap, Prices, Rents, Unemployment
Publication HAL Google Scholar
Résumé After years of high commodity prices, a new era of lower ones, especially for oil, seems likely to persist. This will be challenging for resource-rich countries, which must cope with the decline in income that accompanies the lower prices and the potential widening of internal and external imbalances. This column presents a new VOXEU eBook in which leading economists from academia and the public and private sector examine the shifting landscape in commodity markets and look at the exchange rate, monetary, and fiscal options policymakers have, as well as the role of finance, including sovereign wealth funds, and diversification.
HAL Google Scholar
Résumé This paper investigates whether trading volume and price distortion can be explained by the investor’s bounded rationality. Assuming that agents are bounded by their information access and processing, what are the consequences on market dynamics? We expose the result of simulations in an ABM that considers the liquidity as an endogenous characteristic of the market and allows to design investors as bounded rational. In a call auction market, where two risky assets are exchanged, traders are defined as a mix between fundamentalist and trend-follower outlook. Each one differs as to behaviour, order-placement strategy, mood, knowledge, risk-aversion and investment horizon. We place agents in a context of evolving fundamental values and order placement strategy; they perceive the fundamental but they also have some heterogeneous belief perseverance; and they adapt their orders to the market depth so as to maximise their execution probability and their profit. By adding bounded rationality in their information processing, we show that (1) usual features as trend-follower outlook and heterogeneous investment horizon are important features to generate excess volatility of asset prices and market inefficiency; (2) the learning fundamental value stabilises the market price and the trading volume; (3) the order-placement strategy increases trading volume, but reduces market efficiency and stability; (4) the agent’s mood prevents illiquid market and weakly increases the market volatility as classical noise trader agents; (5) the impatience to sell of traders is always present in the market: the market sell orders are always more numerous than the market buy orders.
Publication HAL Google Scholar
Résumé BACKGROUND: Dementia is a prevalent condition, affecting 5-7% of people aged 60 years and older, and a leading cause of disability in people aged 60 years and older globally. We aimed to examine the association between alcohol use disorders and dementia risk, with an emphasis on early-onset dementia (1·7) in sensitivity analyses on dementia case definition (including Alzheimer's disease) or older study populations. Also, alcohol use disorders were significantly associated with all other risk factors for dementia onset (all p
Publication HAL Google Scholar