La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
A subgradient method with non-monotone line searchJournal articleOrizon P. Ferreira, Geovani N. Grapiglia, E. M. Santos et João Carlos O. Souza, Computational Optimization and Applications, Forthcoming

In this paper we present a subgradient method with non-monotone line search for the minimization of convex functions with simple convex constraints. Different from the standard subgradient method with prefixed step sizes, the new method selects the step sizes in an adaptive way. Under mild conditions asymptotic convergence results and iteration-complexity bounds are obtained. Preliminary numerical results illustrate the relative efficiency of the proposed method.

Underreporting of Top Incomes and Inequality: A Comparison of Correction Methods using Simulations and Linked Survey and Tax DataJournal articleEmmanuel Flachaire, Nora Lustig et Andrea Vigorito, Review of Income and Wealth, Volume n/a, Issue n/a, Forthcoming

Household surveys do not capture incomes at the top of the distribution well. This yields biased inequality measures. We compare the performance of the reweighting and replacing methods to address top incomes underreporting in surveys using information from tax records. The biggest challenge is that the true threshold above which underreporting occurs is unknown. Relying on simulation, we construct a hypothetical true distribution and a “distorted” distribution that mimics an underreporting pattern found in a novel linked data for Uruguay. Our simulations show that if one chooses a threshold that is not close to the true one, corrected inequality measures may be significantly biased. Interestingly, the bias using the replacing method is less sensitive to the choice of threshold. We approach the threshold selection challenge in practice using the Uruguayan linked data. Our findings are analogous to the simulation exercise. These results, however, should not be considered a general assessment of the two methods.

Accounting for subsistence needs in non-market valuation: a simple proposalJournal articleVictor Champonnois et Olivier Chanel, Journal of Environmental Planning and Management, pp. 1-24, Forthcoming

Revealed and stated preference techniques are widely used to assess willingness to pay (WTP) for non-market goods as input to public and private decision-making. However, individuals first have to satisfy subsistence needs through market good consumption, which affects their ability to pay. We provide a methodological framework and derive a simple ex post adjustment factor to account for this effect. We quantify its impacts on the WTP for non-market goods and the ranking of projects theoretically, numerically and empirically. This confirms that non-adjusted WTP tends to be plutocratic: the views of the richest – whatever they are – are more likely to impact decision-making, potentially leading to ranking reversal between projects. We also suggest that the subsistence needs-based adjustment factor we propose has a role to play in value transfer procedures. The overall goal is a better representation of the entire population’s preferences with regard to non-market goods.

Does Affective Forecasting Error Induce Changes in Preferences? Lessons from Danish Soldiers Anticipating Combat in AfghanistanJournal articleOlivier Chanel, Stéphanie Vincent Lyk-Jensen et Jean-Christophe Vergnaud, Defence and Peace Economics, pp. 1-24, Forthcoming

This paper investigates how affective forecasting errors (A.F.E.s), the difference between anticipated emotion and the emotion actually experienced, may induce changes in preferences on time, risk and occupation after combat. Building on psychological theories incorporating the role of emotion in decision-making, we designed a before-and-after-mission survey for Danish soldiers deployed to Afghanistan in 2011. Our hypothesis of an effect from A.F.E.s is tested by controlling for other mechanisms that may also change preferences: immediate emotion, trauma effect – proxied by post-traumatic stress disorder (P.T.S.D.) – and changes in wealth and risk perception. At the aggregate level, results show stable preferences before and after mission. We find positive A.F.E.s for all three emotions studied (fear, anxiety and excitement), with anticipated emotions stronger than those actually experienced. We provide evidence that positive A.F.E.s regarding fear significantly increase risk tolerance and impatience, while positive A.F.E.s regarding excitement strengthen the will to stay in the military. Trauma has no impact on these preferences.

Nursing homes and mortality in Europe: Uncertain causalityJournal articleXavier Flawinne, Mathieu Lefebvre, Sergio Perelman, Pierre Pestieau et Jérôme Schoenmaeckers, Health Economics, Volume n/a, Issue n/a, Forthcoming

The current health crisis has particularly affected the elderly population. Nursing homes have unfortunately experienced a relatively large number of deaths. On the basis of this observation and working with European data (from SHARE), we want to check whether nursing homes were lending themselves to excess mortality even before the pandemic. Controlling for a number of important characteristics of the elderly population in and outside nursing homes, we conjecture that the difference in mortality between those two samples is to be attributed to the way nursing homes are designed and organized. Using matching methods, we observe excess mortality in Sweden, Belgium, Germany, Switzerland, Czech Republic and Estonia but not in the Netherlands, Denmark, Austria, France, Luxembourg, Italy and Spain. This raises the question of the organization and management of these nursing homes, but also of their design and financing.

An inertial proximal point method for difference of maximal monotone vector fields in Hadamard manifoldsJournal articleJoão S. Andrade, Jurandir de O. Lopes et João Carlos de Souza, Journal of Global Optimization, Forthcoming

We propose an inertial proximal point method for variational inclusion involving difference of two maximal monotone vector fields in Hadamard manifolds. We prove that if the sequence generated by the method is bounded, then every cluster point is a solution of the non-monotone variational inclusion. Some sufficient conditions for boundedness and full convergence of the sequence are presented. The efficiency of the method is verified by numerical experiments comparing its performance with classical versions of the method for monotone and non-monotone problems.

Can labour market institutions mitigate the China syndrome? Evidence from regional labour markets in EuropeJournal articleJan-Luca Hennig, The World Economy, Volume n/a, Issue n/a, Forthcoming

This paper investigates how labour market regulations alter the adverse impact of rising import competition from China in European local labour markets between 1997 and 2006. The paper constructs measures of regional exposure to Chinese imports based on previous literature and on regional labour market frictions exploiting involuntary labour reallocations. Taking into account the endogeneity of import competition and its interaction with labour market regulations, the paper finds that regions more exposed to the rise of China have suffered from a reduction in manufacturing employment shares. This shock grows larger with regional labour market frictions; hence, it exacerbates the impact of trade shock on employment. Moreover, the paper finds that employment in public services, and not in construction or private services sector, absorbed the negative shock to the manufacturing sector. The unemployment rate, the labour force participation rate and wages in all sectors are unresponsive to import competition from China.

The Regularity of the Value Function of Repeated Games with Switching CostsJournal articleYevgeny Tsodikovich, Xavier Venel et Anna Zseleva, Mathematics of Operations Research, Forthcoming

We study repeated zero-sum games where one of the players pays a certain cost each time he changes his action. We derive the properties of the value and optimal strategies as a function of the ratio between the switching costs and the stage payoffs. In particular, the strategies exhibit a robustness property and typically do not change with a small perturbation of this ratio. Our analysis extends partially to the case where the players are limited to simpler strategies that are history independent―namely, static strategies. In this case, we also characterize the (minimax) value and the strategies for obtaining it.

Spatial PolarizationJournal articleFabio Cerina, Elisa Dienesch, Alessio Moro et Michelle Rendall, The Economic Journal, Forthcoming

We document the emergence of spatial polarisation in the United States during the 1980–2008 period. This phenomenon is characterised by stronger employment polarisation in larger cities, both at the occupational and the worker levels. We quantitatively evaluate the role of technology in generating these patterns by constructing and calibrating a spatial equilibrium model. We find that faster skill-biased technological change in larger cities can account for a substantial fraction of spatial polarisation in the United States. Counterfactual exercises suggest that the differential increase in the share of low-skilled workers across city size is due mainly to the large demand by high-skilled workers for low-skilled services and, to a smaller extent, to the higher complementarity between low- and high-skilled workers in production relative to middle-skilled workers.

Private Exploitation of the North-Western Sahara Aquifer SystemJournal articleAmine Chekireb, Julio Goncalves, Hubert Stahn et Agnès Tomini, Environmental Modeling & Assessment, Forthcoming

We formulate a hydro-economic model of the North-Western Sahara Aquifer System (NWSAS) to assess the effects of intensive pumping on the groundwater stock and examine the subsequent consequences of aquifer depletion. This large system comprises multi-layer reservoirs with vertical exchanges, all exploited under open access properties. We first develop a theoretical model to account for relevant features of the NWSAS by introducing, in the standard Gisser-Sanchez model, a non-stationary demand and quadratic stock-dependent cost functions. In the second step, we calibrate parameters values using data from the NWSAS over 1955–2000. We finally simulate the time evolution of the aquifer system with exploitation under an open-access regime. We specifically examine time trajectories of the piezometric levels in the two reservoirs, the natural outlets, and the modification of water balances. We find that natural outlets of the two reservoirs might be totally dried before 2050.