Publications

Abstract Les analyses coûts-bénéfices constituent un moyen pour le décideur public comme privé de rationaliser ses choix. Le processus semble transparent et le traitement des préférences égalitaire, puisque les préférences de chaque individu sont prises en compte de façon similaire lors de l’agrégation. Toutefois, en présence de composantes non marchandes évaluées sur la base des préférences de la population, les individus sont limités dans l’expression de leurs préférences, à la fois par leur revenu et par leur besoin de subsistance. Nous étudions les conséquences de ces contraintes sur la révélation des préférences et sur l’évaluation monétaire des biens non marchands. Nous trouvons qu’elles amènent à favoriser implicitement les préférences des individus à revenu élevé. Se pose alors la question de la correction des évaluations monétaires lors du traitement des préférences individuelles.
Keywords Economics, Health policy, Environmental policy, Consumer preference, Environment and public health
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Abstract Economic growth in advanced countries has slowed in successive stages since the 1970s and, since the crisis, has fallen to a historical low compared with the 20th century. This slowdown is mainly attributable to weaker growth in total factor productivity. In emerging countries, the situation varies: in some countries, such as South Korea and Chile, GDP per capita have been converging for several decades; in others, such as Argentina, Brazil and Mexico, relative GDP per capita has stagnated or even declined. While weak long-term growth in these latter countries can be attributed to a lack of appropriate institutions, the widespread slowdown observed in advanced countries is more difficult to interpret. One possible explanation that we explore is the decline in real interest rates since the 1990s. A circular relationship appears to exist between interest rates and productivity: productivity determines long-term returns on capital and thereby interest rates; interest rates in turn determine the minimum productivity expected from investment projects. The decline in real interest rates, which is in part attributable to demographic factors, may have led to a slowdown in productivity by making an increasing number of unproductive companies and projects profitable. We illustrate this circular relationship using a cross-country panel regression. One way of breaking out of the circular relationship would be via a new technological revolution linked to the digital economy, or, in countries where there is still room for convergence, via structural reforms to improve the diffusion of Information and Communication Technologies (ICT).
Keywords Growth, Total factor productivity, Real interest rates, Digital economy
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Abstract In their efforts to affect regulations, firms have developed specific strategies to exploit scientific uncertainty. They have manufactured doubt by hiring and funding dissenting scientists, by producing and publicizing favorable scientific findings and by generally concealing their involvement in biased research. We propose a new model to study the interplay between scientific uncertainty, firms' miscommunication and public policies. The government is benevolent but populist, and maximizes social welfare as perceived by citizens. The industry can produce costly reports showing that its activity is not harmful. Citizens are unaware of the industry's miscommunication. We first characterize the industry's optimal miscommunication policy. The industry notably ceases miscommunicating abruptly when scientists' belief reaches a critical threshold. We identify a natural condition under which miscommunication is stronger under a tax on emissions than under command and control. We then analyze research funding. A populist government may support research to enable firms to falsely reassure citizens. Establishing an independent research agency helps limit the welfare losses induced by populist policies.
Keywords Populist Policies, Environmental Policy Instruments, Scientific Uncertainty, Research Funding
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Abstract Our new approach to mobility measurement involves separating out the valuation of positions in terms of individual status (using income, social rank, or other criteria) from the issue of movement between positions. The quantification of movement is addressed using a general concept of distance between positions and a parsimonious set of axioms that characterize the distance concept and yield a class of aggregative indices. This class of indices induces a superclass of mobility measures over the different status concepts consistent with the same underlying data. We investigate the statistical inference of mobility indices using two well‐known status concepts, related to income mobility and rank mobility. We also show how our superclass provides a more consistent and intuitive approach to mobility, in contrast to other measures in the literature, and illustrate its performance using recent data from China.
Keywords Measurement axiomatic approach, Rank mobility, Income mobility
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Abstract This study investigates the empirical association of oil prices with economic activity in developed open economy namely: The United States by using the wavelet transform framework. This methodology enables the decomposition of time-series at different time-frequencies. In this study, we have used maximal overlap discrete wavelet transform, wavelet covariance, wavelet correlation, continuous wavelet power spectrum, wavelet coherence spectrum and wavelet based Granger causality approaches to analyze the relationship between oil prices and economic activity. The present study uses month frequency data for the period of 1979M1-2013M7. The results indicate that oil prices have positive impact on economic activity and the feedback effect exists between oil prices and economic activity.
Keywords Discrete wavelet analysis, Wavelet coherence, Oil prices, Economic activity
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Abstract This paper proposes a new model with time-varying slope coefficients. Our model, called CHAR, is a Cholesky-GARCH model, based on the Cholesky decomposition of the conditional variance matrix introduced by Pourahmadi (1999) in the context of longitudinal data. We derive stationarity and invertibility conditions and prove consistency and asymptotic normality of the Full and equation-by-equation QML estimators of this model. We then show that this class of models is useful to estimate conditional betas and compare it to the approach proposed by Engle (2016). Finally, we use real data in a portfolio and risk management exercise. We find that the CHAR model outperforms a model with constant betas as well as the dynamic conditional beta model of Engle (2016).
Keywords Covariance, Conditional betas, Multivariate-GARCH
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Abstract We compare how the long-run distribution of fishing activities is affected in multispecies fisheries when facing different second-best control rules: (1) species-specific landing regulation, and (2) global input regulation. We show how this depends on the economic returns and on the type of ecological interaction considered. We highlight specifically that fishing effort does not necessarily increase on nontargeted species and decrease on targeted species, and that the characterization of second-best efficient instruments may differ drastically depending on the nature of the interaction.
Keywords Multispecies fisheries, Second-best management, Bioeconomic models, Fishing, Effort distribution, Biological interactions, Pêcherie, Bioéconomie
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Abstract This paper revisits the optimal population size problem in a continuous time Ramsey setting with costly child rearing and both intergenerational and intertemporal altruism. The social welfare functions considered range from the Millian to the Benthamite. When population growth is endogenized, the associated optimal control problem involves an endogenous effective discount rate depending on past and current population growth rates, which makes preferences intertemporally dependent. We tackle this problem by using an appropriate maximum principle. Then we study the stationary solutions (balanced growth paths) and show the existence of two admissible solutions except in the Millian case. We prove that only one is optimal. Comparative statics and transitional dynamics are numerically derived in the general case.
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Abstract Avoiding to assign emerging market countries a ‘typical’ behaviour, this article considers the heterogeneity across them and through time to predict their sovereign default episodes. Moreover, it focuses on the imbalance between defaulted debt and GDP. For the first time, we use a panel nonlinear regime-switching model whose explanatory factors have a different impact on sovereign default, depending on the regime the country belongs to. We mitigate some common views of the literature (in particular the ‘serial default’ theory) and identify countries deserving to be monitored carefully, because of a higher exposure to sovereign default risk.
Keywords Vulnerability regimes, Emerging countries, PSTR model, Sovereign debt
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Abstract In 2002, the Israeli government decided to build a wall inside the occupied West Bank. The wall had a marked effect on the access to land and water resources as well as to the Israeli labour market. It is difficult to include the effect of the wall in an econometric model explaining poverty dynamics as the wall was built in the richer region of the West Bank. So a diff-in-diff strategy is needed. Using a Bayesian approach, we treat our two-period repeated cross-section data set as an incomplete data problem, explaining the income-to-needs ratio as a function of time invariant exogenous variables. This allows us to provide inference results on poverty dynamics. We then build a conditional regression model including a wall variable and state dependence to see how the wall modified the initial results on poverty dynamics. We find that the wall has increased the probability of poverty persistence by 58 percentage points and the probability of poverty entry by 18 percentage points.
Keywords Bayesian inference, Pseudo panels, Data augmentation, Walls, Poverty dynamics
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Abstract We document strong and robust negative correlations between the length of the title of an economics article and different measures of scientific quality. Analyzing all articles published between 1970 and 2011 and referenced in EconLit, we find that articles with shorter titles tend to be published in better journals, to be more cited and to be more innovative. These correlations hold controlling for unobserved time-invariant and observed time varying characteristics of teams of authors. (C) 2018 Elsevier B.V. All rights reserved.
Keywords Novelty, Citations, Journal quality, Title length
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