Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Air Pollution and Health: Economic ImplicationsBook chapterOlivier Chanel, In: Handbook of Labor, Human Resources and Population Economics, Springer, Cham, Forthcoming
Sovereign bond market integration in the euro area: a new empirical conceptualizationJournal articleGilles Dufrénot, Fredj Jawadi et Zied Ftiti, Annals of Operations Research, Forthcoming

This paper proposes a new empirical conceptualization of financial integration of sovereign bond markets in the euro area. We introduce a methodology based on the joint testing of the assumptions of efficient market and convergence/divergence of the yield spreads. We test these assumptions by proposing parametric and non-parametric techniques. We find that markets have been more fragmented than usually advocated in the literature. We also show that the information contained in the fundamentals are not always fully reflected in the spreads, which suggests that either they have insignificant effects, or that their coefficients in the spread equations appear with the wrong sign.

When Is Product Personalization Profit-Enhancing? A Behavior-Based Discrimination ModelJournal articleDidier Laussel et Joana Resende, Management Science, Forthcoming

This paper investigates duopoly competition when horizontally differentiated firms are able to make personalized product-price offers to returning customers, within a behavior-based discrimination model. In the second period, firms can profile old customers according to their preferences, selling them targeted products at personalized prices. Product-price personalization (PP) allows firms to retain all old customers, eliminating second-period customer poaching. The overall profit effects of PP are shown to be ambiguous. In the second period, PP improves the matching between customers’ preferences and firms’ offers, but firms do not make any revenues in the rival’s turf. In the Bertrand outcome, second-period profits only increase for both firms if the size of their old turfs are not too different or initial products are not too differentiated. However, the additional second-period profits may be offset by lower first-period profits. PP is likely to increase firms’ overall discounted profits when consumers’ (firms’) discount factor is low (high) and firms’ initial products are exogenous and sufficiently different. When the location of initial products is endogenous, profits are hurt because of an additional location (strategic) effect aggravating head-to-head competition in the first period. Likewise, when a fraction of active consumers conceals their identity, PP increases second-period profits at the cost of aggressive first-period price competition. Finally, we show that the room for profitable PP enlarges considerably if firms rely on PP as an effective device to sustain tacit collusive outcomes, with firms credibly threatening to respond to first-period price deviations with second-period aggressive relocations of their standard products.

This paper was accepted by Matthew Shum, marketing.

Do firms always benefit from the presence of active customers?Journal articleDidier Laussel, Applied Economics, pp. 1-16, Forthcoming

We study price personalization in a two period duopoly with horizontally differentiated products. In the second period, a firm has collected detailed information on its old customers, using it to engage in price personalization. Customers, when returning to buy, may choose to incur a cost in order to access the standard offer of their previous provider in addition to its personalized offer and the standard offer of its rival. The analysis confirms that firms’ second period profits are boosted when consumers are active in this sense (being equal to perfect price discrimination ones when initial market hares do not differ too much) but it reveals that this advantage is dissipated and possibly over-dissipated by the resulting fierce first-period competition for the market. Two-period aggregate profits are smaller with active customers provided the consumers are naive and/or the firms patient enough. Consumers’ access to both personalized and standard firms’ offers which benefit the oligopolists in mature markets may plausibly hurt them in emergent ones. The equilibrium is shown not to depend on the level of the cost as long as it is below some critical value.

Limited‐tenure concessions for collective goodsJournal articleNicolas Quérou, Agnès Tomini et Christopher Costello, Journal of Economic Dynamics and Control, pp. 104484, Forthcoming

We analyze theoretically an institution called a “limited-tenure concession” for its ability to induce efficient public goods contribution and common-pool resource extraction. The basic idea is that by limiting the tenure over which an agent can enjoy the public good, but offering the possibility of renewal contingent on ample private provision of that good, efficient provision may be induced. We first show in a simple repeated game setting that limited-tenure concessions can incentivize socially-efficient provision of public goods. We then analyze the ability of this instrument to incentivize the first best provision for common-pool natural resources such as fish and water, thus accounting for spatial connectivity and growth dynamics of the resource. The duration of tenure and the dispersal of the resource play pivotal roles in whether this limited-tenure concession induces the socially optimal private provision. Finally, in a setting with costly monitoring, we discuss the features of a concession contract that ensure first-best behavior, but at least cost to the implementing agency.

Coercivity and generalized proximal algorithms: application—traveling around the worldJournal articleErik A. Papa Quiroz, Antoine Soubeyran et Paulo R. Oliveira, Annals of Operations Research, Forthcoming

We present an inexact proximal point algorithm using quasi distances to solve a minimization problem in the Euclidean space. This algorithm is motivated by the proximal methods introduced by Attouch et al., section 4, (Math Program Ser A, 137: 91–129, 2013) and Solodov and Svaiter (Set Valued Anal 7:323–345, 1999). In contrast, in this paper we consider quasi distances, arbitrary (non necessary smooth) objective functions, scalar errors in each objective regularized approximation and vectorial errors on the residual of the regularized critical point, that is, we have an error on the optimality condition of the proximal subproblem at the new point. We obtain, under a coercivity assumption of the objective function, that all accumulation points of the sequence generated by the algorithm are critical points (minimizer points in the convex case) of the minimization problem. As an application we consider a human location problem: How to travel around the world and prepare the trip of a lifetime.

Valuation of ecosystem services and social choice: the impact of deliberation in the context of two different aggregation rulesJournal articleMariam Maki Sy, Charles Figuières, Hélène Rey-Valette, Richard B. Howarth et Rutger De Wit, Social Choice and Welfare, Forthcoming

This paper describes an empiric study of aggregation and deliberation—used during citizens’ workshops—for the elicitation of collective preferences over 20 different ecosystem services (ESs) delivered by the Palavas coastal lagoons located on the shore of the Mediterranean Sea close to Montpellier (S. France). The impact of deliberation is apprehended by comparing the collectives preferences constructed with and without deliberation. The same aggregation rules were used before and after deliberation. We compared two different aggregation methods, i.e. Rapid Ecosystem Services Participatory Appraisal (RESPA) and Majority Judgement (MJ). RESPA had been specifically tested for ESs, while MJ evaluates the merit of each item, an ES in our case, in a predefined ordinal scale of judgment. The impact of deliberation was strongest for the RESPA method. This new information acquired from application of social choice theory is particularly useful for ecological economics studying ES, and more practically for the development of deliberative approaches for public policies.

Overreaction and momentum in the Vietnamese stock marketJournal articleLe Quy Duong et Philippe Bertrand, Managerial Finance, Forthcoming

Purpose
Although the solid empirical proof of momentum is documented in various stock markets, there are many debates among academics with respect to the source of momentum profit. The first aim of this paper is intensively re-examine the momentum profit in Vietnam, an important emerging market. Secondly, the authors study the return predictability of a measure of investors’ overreaction, then examine whether the momentum effect in Vietnam is explained by overreaction.
Design/methodology/approach
Using the weekly data of more than 300 non-financial Vietnamese stocks during 2009–2019, the authors build a measure of investors’ overreaction, which is based on trading volume and the sign of stock returns. Consequently, to investigate whether momentum exits after controlling for overreaction, the authors carefully compare trading strategies based on overreaction with price momentum strategies using adjusted returns and double sorts on past returns and levels of overreaction.
Findings
The article makes three main findings. Firstly, the authors discover the empirical evidence of momentum in the Vietnamese equity market. Secondly, the measure of overreaction could be a predictor of Vietnamese stock returns. Stocks that have experienced a stronger upward overreaction provide a higher average return. Finally, returns on trading strategies based on overreaction are robust after adjusting for momentum, while returns on momentum portfolios become insignificant after adjusting for overreaction. By double-sorting, the authors document that holding past returns constant, the average returns of portfolios rise monotonically with their measure of overreaction. Hence, the momentum profit in Vietnam arises from investors’ overreaction.
Originality/value
The paper extends previous research on the behavioral explanation of momentum in emerging stock markets, which has not been fully exploited in the literature.

One size may not fit all: Financial fragmentation and European monetary policiesJournal articleCéline Gimet et Marie-Hélène Gagnon, Review of International Economics, Forthcoming

This article investigates the impact of European Central Bank policies on credits considering financial and banking fragmentation. Using European data from the past decade, we estimate SVAR models to analyze the regional impact of conventional and unconventional measures on price and volume indicators of fragmentation. The risk-taking channel is studied using GVAR models to document the national consequences of this fragmentation. We find that unconventional measures increase credit in peripheral countries. Monetary policies alleviate fragmentation, but mostly in terms of price dispersion rather than credit volume. Finally, unconventional measures imply a rebalancing of European bank assets in favor of foreign currency denominated-assets.

Nudging for Lockdown: Behavioral Insights from an Online ExperimentJournal articleThierry Blayac, Dimitri Dubois, Sebastien Duchêne, Phu Nguyen-Van, Ismael Rafai, Bruno Ventelou et Marc Willinger, Social Psychology, Forthcoming

We test the effectiveness of a social comparison nudge (SCN) to enhance lockdown compliance during the COVID-19 pandemic using a French representative sample (N = 1,154). Respondents were randomly assigned to a favorable/unfavorable informational feedback (daily road traffic mobility patterns, in Normandy - a region of France) on peer lockdown compliance. Our dependent variable was the intention to comply with a possible future lockdown. We controlled for risk, time, and social preferences and tested the effectiveness of the nudge. We found no evidence of the effectiveness of the SCN among the whole French population, but the nudge was effective when its recipient and the reference population shared the same geographical location (Normandy). Exploratory results on this subsample (N = 52) suggest that this effectiveness could be driven by noncooperative individuals.