Publications

Recent Developments in Macro-Econometric Modeling: Theory and ApplicationsGilles Dufrénot, Fredj Jawadi et Alexander Mihailov, Econometrics, Volume 6, Issue 2, pp. 25, 2018

Developments in macro-econometrics have been evolving since the aftermath of the Second World War.[...]

Top Incomes, Heavy Tails, and Rank-Size RegressionsChristian Schluter, Econometrics, Volume 6, Issue 1, pp. 10, 2018

In economics, rank-size regressions provide popular estimators of tail exponents of heavy-tailed distributions. We discuss the properties of this approach when the tail of the distribution is regularly varying rather than strictly Pareto. The estimator then over-estimates the true value in the leading parametric income models (so the upper income tail is less heavy than estimated), which leads to test size distortions and undermines inference. For practical work, we propose a sensitivity analysis based on regression diagnostics in order to assess the likely impact of the distortion. The methods are illustrated using data on top incomes in the UK.

When do social cues and scientific information affect stated preferences? Insights from an experiment on air pollutionDominique Ami, Frédéric Aprahamian, Olivier Chanel et Stéphane Luchini, Journal of Choice Modelling, Volume 29, Issue C, pp. 33-46, 2018

Stated preference surveys are usually carried out in one session, without any follow-up interview after respondents have had the opportunity to experience the public goods or policies they were asked to value. Consequently, a stated preference survey needs to be designed so as to provide respondents with all the relevant information, and to help them process this information so they can perform the valuation exercise properly. In this paper, we study experimentally an elicitation procedure in which respondents are provided with a sequence of different types of information (social cues and objective information) that allows them to sequentially revise their willingness-to-pay (WTP) values. Our experiment was carried out in large groups using an electronic voting system which allows us to construct social cues in real time. To analyse the data, we developed an anchoring-type structural model that allows us to estimate the direct effect (at the current round) and the indirect effect (on subsequent rounds) of information. Our results shed new light on the interacted effect of social cues and objective information: social cues have little or no direct effect on WTP values but they have a strong indirect effect on how respondents process scientific information. Social cues have the most noticeable effect on respondents who initially report a WTP below the group average but only after receiving additional objective information about the valuation task. We suggest that the construction and the provision of social cues should be added to the list of tools and controls for stated preference methods.

Targeting the key player: An incentive-based approachMohamed Belhaj et Frédéric Deroian, Journal of Mathematical Economics, Volume 79, Issue C, pp. 57-64, 2018

We consider a network game with local complementarities. A policymaker, aiming at minimizing or maximizing aggregate effort, contracts with a single agent on the network to trade effort change against transfer. The policymaker has to find the best agent and the optimal contract to offer. Our study shows that for all utilities with linear best-responses, it only takes two statistics about the position of each agent on the network to identify the key player: the Bonacich centrality and the self-loop centrality. We also characterize key players under linear quadratic utilities for various contractual arrangements.

Econometrics and Income InequalityMartin Biewen et Emmanuel Flachaire, Econometrics, Volume 6, Issue 4, pp. 42, 2018

It is well-known that, after decades of non-interest in the theme, economics has experienced a proper surge in inequality research in recent years. [...]

Regional paleoclimates and local consequences: Integrating GIS analysis of diachronic settlement patterns and process-based agroecosystem modeling of potential agricultural productivity in Provence (France)Daniel A. Contreras, Eneko Hiriart, Alberte Bondeau, Alan Kirman, Joël Guiot, Loup Bernard, Romain Suarez et Sander Van Der Leeuw, PloS one, Volume 13, Issue 12, pp. e0207622, 2018

Holocene climate variability in the Mediterranean Basin is often cited as a potential driver of societal change, but the mechanisms of this putative influence are generally little explored. In this paper we integrate two tools–agro-ecosystem modeling of potential agricultural yields and spatial analysis of archaeological settlement pattern data–in order to examine the human consequences of past climatic changes. Focusing on a case study in Provence (France), we adapt an agro-ecosystem model to the modeling of potential agricultural productivity during the Holocene. Calibrating this model for past crops and agricultural practices and using a downscaling approach to produce high spatiotemporal resolution paleoclimate data from a Mediterranean Holocene climate reconstruction, we estimate realistic potential agricultural yields under past climatic conditions. These serve as the basis for spatial analysis of archaeological settlement patterns, in which we examine the changing relationship over time between agricultural productivity and settlement location. Using potential agricultural productivity (PAgP) as a measure of the human consequences of climate changes, we focus on the relative magnitudes of 1) climate-driven shifts in PAgP and 2) the potential increases in productivity realizable through agricultural intensification. Together these offer a means of assessing the scale and mechanisms of the vulnerability and resilience of Holocene inhabitants of Provence to climate change. Our results suggest that settlement patterns were closely tied to PAgP throughout most of the Holocene, with the notable exception of the period from the Middle Bronze Age through the Early Iron Age. This pattern does not appear to be linked to any climatically-driven changes in PAgP, and conversely the most salient changes in PAgP during the Holocene cannot be clearly linked to any changes in settlement pattern. We argue that this constitutes evidence that vulnerability and resilience to climate change are strongly dependent on societal variables.

Data from: Regional paleoclimates and local consequences: Integrating GIS analysis of diachronic settlement patterns and process-based agroecosystem modeling of potential agricultural productivity in Provence (France)Daniel Contreras, Eneko Hiriart, Alberte Bondeau, Alan Kirman, Joël Guiot, Loup Bernard, Romain Suarez et Sander Van Der Leeuw, 2018

Holocene climate variability in the Mediterranean Basin is often cited as a potential driver of societal change, but the mechanisms of this putative influence are generally little explored. In this paper we integrate two tools - agro-ecosystem modeling of potential agricultural yields and spatial analysis of archaeological settlement pattern data - in order to examine the human consequences of past climatic changes. Focusing on a case study in Provence (France), we adapt an agro-ecosystem model to the modeling of potential agricultural productivity during the Holocene. Calibrating this model for past crops and agricultural practices and using a downscaling approach to produce high spatiotemporal resolution paleoclimate data from a Mediterranean Holocene climate reconstruction, we estimate realistic potential agricultural yields under past climatic conditions. These serve as the basis for spatial analysis of archaeological settlement patterns, in which we examine the changing relationship over time between agricultural productivity and settlement location. Using potential agricultural productivity (PAgP) as a measure of the human consequences of climate changes, we focus on the relative magnitudes of 1) climate-driven shifts in PAgP and 2) the potential increases in productivity realizable through agricultural intensification. Together these offer a means of assessing the scale and mechanisms of the vulnerability and resilience of Holocene inhabitants of Provence to climate change. Our results suggest that settlement patterns were closely tied to PAgP throughout most of the Holocene, with the notable exception of the period from the Middle Bronze Age through the Early Iron Age. This pattern does not appear to be linked to any climatically-driven changes in PAgP, and conversely the most salient changes in PAgP during the Holocene cannot be clearly linked to any changes in settlement pattern. We argue that this constitutes evidence that vulnerability and resilience to climate change are strongly dependent on societal variables.

Stock Market Bubble Migration: From Shanghai to Hong Kong: Essays in Honor of Georges PratEric Girardin, Roselyne Joyeux et Shuping Shi, 2018-12, pp. 173-192, Springer International Publishing, 2018

The speculative nature of the stock market in Mainland China has attracted the attention of many observers. However while the degree of integration of the Hong Kong market with its Mainland counterpart has monopolized the interest of researchers, they have neglected the diffusion of bubbles from the latter to the former. We thus propose the first study of such bubble migration. Focusing on the period 2005–2017, we use the Phillips et al. (Int Econ Rev 56:1043–1078, 2015a; Int Econ Rev 52:201–226, 2015b) recursive explosive root test to detect and date speculative episodes in both markets. We then implement the Greenaway-McGrevy and Phillips (NZ Econ Pap 50:88–113, 2016) methodology to detect the presence of migration between the two markets. We detect significant, but dwindling, bubble migration from Shanghai to Hong Kong.

Federal minimum wage hikes do reduce teenage employment. A replication study of Bazen & Marimoutou (Oxford Bulletin of Economics and Statistics, 2002)Stephen Bazen et Vêlayoudom Marimoutou, International Journal for Re-Views in Empirical Economics, Volume 2, Issue 2018-5, 2018

In 2002 we published a paper in which we used state space time series methods to analyse the teenage employment-federal minimum wage relationship in the US (Bazen and Marimoutou, 2002). The study used quarterly data for the 46 year period running from 1954 to 1999. We detected a small, negative but statistically significant effect of the federal minimum wage on teenage employment, at a time when some studies were casting doubt on the existence of such an effect. In this note we re-estimate the original model with a further 16 years of data (up to 2015). We find that the model satisfactorily tracks the path of the teenage employment-population ratio over this 60 year period, and yields a consistently negative and statistically significant effect of minimum wages on teenage employment. The conclusion reached is the same as in the original paper, and the elasticity estimates very similar: federal minimum wage hikes lead to a reduction in teenage employment with a short run elasticity of around – 0.13. The estimated long run elasticity of between – 0.37 and – 0.47 is less stable, but is nevertheless negative and statistically significant.

Entrepreneurial motivation and business performance: evidence from a French Microfinance InstitutionRenaud Bourlès et Anastasia Cozarenco, Small Business Economics, Volume 51, Issue 4, pp. 943-963, 2018

This article examines the link between entrepreneurial motivation and business performance in the French microfinance context. Using hand-collected data on business microcredits from a Microfinance Institution (MFI), we provide an indirect measure of entrepreneurial success through loan repayment performance. Controlling for the endogeneity of entrepreneurial motivation in a bivariate probit model, we find that “necessity entrepreneurs” are more likely to have difficulty repaying their microcredits than “opportunity entrepreneurs”. However, type of motivation does not appear to make a difference to business survival. We test for the robustness of our results using parametric duration models and show that necessity entrepreneurs experience difficulties in loan repayment earlier than their opportunity counterparts, corroborating our initial findings. Our results are also robust to a sharper analysis of motivation, focusing on unemployment (on the necessity side) and non-pecuniary benefits from success (on the opportunity side).