L’économie des invasions biologiques : vers une hiérarchisation des stratégies de gestionBook chapterPierre Courtois, Charles Figuières, César Martinez, Gaël Thébaud et Alban Thomas, In: Crises sanitaires en agriculture, C. Lannou, J-Y. Rasplus, S. Soubeyrand, M. Gautier et J-P. Rossi (Eds.), 2023-01, pp. 238-250, Éditions Quae, 2023
The impact of academic information supply and familiarity on preferences for ecosystem servicesJournal articleMariam Maki Sy, Hélène Rey-Valette, Charles Figuières, Monique Simier et Rutger De Wit, Ecological Economics, Volume 183, pp. 106959, 2021

Preferences elicitation can be a challenging exercise for citizens participating in assessment surveys. It is even more challenging when it comes to complex and unfamiliar ecosystems and the threatened ecosystem services they provide. Making people aware of the characteristics of the ecosystem services being valued is determinant for the assessment process. We investigated the impact of familiarity and academic information supply on people's preferences for twenty selected ecosystem services of French Mediterranean coastal lagoons. The results show that regardless of familiarity and information supply, there is a strong consensus about the highest importance of regulation and maintenance ecosystem services as well as environmental education and research opportunity ecosystem services. By contrast, nine of the cultural ecosystem services, together with two provisioning ecosystem services showed heterogeneous preferences among the different citizen groups. Using a combination of descriptive and inferential statistics these eleven ecosystem services split up into three clusters characterized as (i) contemplative leisure, (ii) heritage, and (iii) consumptive activities. Familiarity and academic information supply had a strong impact on the preferences for these three clusters of ecosystem services.

How to turn crowding-out into crowding-in? An innovative instrument and some law-related examplesJournal articleAntoine Beretti, Charles Figuières et Gilles Grolleau, European Journal of Law and Economics, Volume 48, Issue 3, pp. 417-438, 2019

Using a simple decision-theoretic approach, we formalize how agents with different kinds of intrinsic motivations react to the introduction of monetary incentives. We contend that empirical results supporting the existence of a crowding-out effect under various legal procedures hide a more complex reality, where some individuals contribute thanks to these additional monetary incentives while others reduce their contributions. Our approach allows us to study the theoretical ability of the self selection mechanism (Mellstrom and Johannesson in J Eur Econ Assoc 6:845-863, 2008; Beretti et al. in Kyklos 66(1):63-77, 2013) to reduce the likelihood to backfire against the cause it is meant to promote. This mechanism consists of a monetary payment for the pro-social behavior and it offers agents the choice to either keep the money for themselves or to direct it to a charity. We show that this legal procedure dominates others more classical procedures because it taps wisely into the motivational heterogeneity of individuals. It uses a self-selection mechanism to match adequate monetary incentives with individuals' types regarding intrinsic motivations. It may even turn a situation subject to crowding-out into a crowding-in outcome.

A Tale of Two DiversitiesJournal articlePierre Courtois, Charles Figuières et Chloe Mulier, Ecological Economics, Volume 159, Issue C, pp. 133-147, 2019

Efficient biodiversity management strategies aim to allocate conservation efforts so as to maximize diversity in ecological systems. Toward this end, defining a diversity criterion is an important but challenging task, as several different indices can be used as biodiversity measures. This paper elicits and compares two criteria for biodiversity conservation based on indices stemming from different disciplines: Weitzman's index in economics and Rao's index in ecology. These indices use different approaches to combine information about measures of (1) the probability distributions of the species that are present in an ecosystem (i.e. survival probabilities) and (2) the degree of dissimilarity between these species. As an important step toward in situ conservation criteria, we add to these elements information about (3) the ecological interactions that take place between species. Considering a simple three-species ecosystem, we show that criterion choice has palpable policy implications, as it can sometimes lead to divergent management recommendations. We disentangle the roles played by elements (1), (2) and (3) in the ranking of outcomes, which allows us to highlight several specificities of the two criteria. An important result is that, other things being equal, Weitzman's in situ ranking tends to favor robust species that are least concerned with extinction, while Rao's in situ ranking generally gives priority to more vulnerable species that are closer to extinction.

Identifying Consensus on Coastal Lagoons Ecosystem Services and Conservation Priorities for an Effective Decision Making: A Q ApproachJournal articleMariam Maki Sy, Hélène Rey-Valette, Monique Simier, Vanina Pasqualini, Charles Figuières et Rutger De Wit, Ecological Economics, Volume 154, Issue C, pp. 1-13, 2018

Coastal lagoons ecosystems, while representing benefits for the local populations, have been subjected to high anthropogenic pressures for decades. Hence, conservation measures of these ecosystems are urgently needed and should be combined with their sustainable uses. To address these issues, new research avenues for decision support systems have emphasized the role of the assessment of ecosystem services for establishing conservation priorities by avoiding monetarization approaches. These approaches, because they flatten the various values of nature by projecting them on the single monetary dimension, are often rejected by the stakeholders. We undertake a Q analysis to identify levels of consensus and divergence among stakeholders on the prioritization of ecosystem services provided by two French Mediterranean coastal lagoons areas. The results highlighted that there is a strong consensus among categories of stakeholders in the study sites about the paramount importance of regulation and maintenance services. Three groups of stakeholders, each sharing the same points of view regarding ecosystem services conservation, were identified for each study site. As a non-monetary valuation, Q methodology is very instrumental for the new pluralistic approach of decision support by capturing the values expressed by the stakeholders, without triggering a rejection reflex due to the monetarization.

A Cost–Benefit Approach for Prioritizing Invasive SpeciesJournal articlePierre Courtois, Charles Figuières, Chloe Mulier et Joakim Weill, Ecological Economics, Volume 146, Issue C, pp. 607-620, 2018

Biological invasions entail massive biodiversity losses and tremendous economic impacts that justify significant management efforts. Because the funds available to control biological invasions are limited, there is a need to identify priority species. In this paper, we first review current invasive species prioritization methods and explicitly highlight their strengths and pitfalls. We then construct a cost–benefit optimization framework that offers the theoretical foundations of a simple method for the management of multiple invasive species under a limited budget. We provide an algorithm to operationalize this framework and render explicit the assumptions required to satisfy the management objective.

The MBR intertemporal choice criterion and Rawls’ just savings principleJournal articleCharles Figuières, Ngo Van Long et Mabel Tidball, Mathematical Social Sciences, Volume 85, Issue C, pp. 11-22, 2017

This paper provides general theorems about the control that maximizes the mixed Bentham–Rawls (MBR) criterion for intergenerational justice, which was introduced in Alvarez-Cuadrado and Long (2009). We establish sufficient concavity conditions for a candidate trajectory to be optimal and unique. We show that the state variable is monotonic under rather weak conditions. We also prove that inequality among generations, captured by the gap between the poorest and the richest generations, is lower when optimization is performed under the MBR criterion rather than under the discounted utilitarian criterion. A quadratic example is also used to perform comparative static exercises: it turns out, in particular, that the larger the weight attributed to the maximin part of the MBR criterion, the better-off the less fortunate generations. All those properties are discussed and compared with those of the discounted utilitarian (DU, Koopmans 1960) and the rank-discounted utilitarian (RDU, Zuber and Asheim, 2012) criteria. We contend they are in line with some aspects of the rawlsian just savings principle.

The determinants of households' flood mitigation decisions in France - on the possibility of feedback effects from past investmentsJournal articleClaire Richert, Katrin Erdlenbruch et Charles Figuières, Ecological Economics, Volume 131, Issue C, pp. 342-352, 2017

In this paper, we investigate the determinants of private flood mitigation in France. We conducted a survey among 331 inhabitants of two flood-prone areas and collected data on several topics, including individual flood mitigation, risk perception, risk experience, and sociodemographic characteristics. We estimate discrete choice models to explain either the precautionary measures taken by the household, or the intention to undertake such measures in the future. Our results confirm that the Protection Motivation Theory is a relevant framework to describe the mechanisms of private flood mitigation in France, highlighting in particular the importance of threat appraisal and previous experience of floods. Some sociodemographic features also play a significant role in explaining private flood mitigation. We also observed that respondents who had already taken precautionary measures have a lower perception of the risk of flooding than respondents who planned to implement such measures at the time of the survey. This result can be explained by the existence of a feedback effect of having taken precautionary measures on risk perception. If subsequent studies support this assumption, it would imply that intended measures, rather than implemented ones, should be examined to explore further the determinants of private flood mitigation.

Choice overload, coordination and inequality: three hurdles to the effectiveness of the compensation mechanism?Journal articleEstelle Midler, Charles Figuières et Marc Willinger, Social Choice and Welfare, Volume 45, Issue 3, pp. 513-535, 2015

We test the effectiveness of a compensation mechanism, adapted from Varian (Am Econ Rev 84(5):1278–1293, 1994 ). When a negative externality is produced the mechanism allows agents suffering from it to compensate those who reduce its production, by way of transfers implemented via a two-stage design. We investigate various factors that might affect the likelihood that subjects coordinate on a Pareto optimum: the size of the strategy space, the number of subgame perfect equilibria and inequality of the payoff distribution. Our experimental findings suggest that the mechanism’s effectiveness crucially depends on the final payoff distribution (after transfers). It is also strongly negatively affected by the size of the strategy space. Finally, the impact of the number of equilibria on coordination only has a weak negative effect. Copyright Springer-Verlag Berlin Heidelberg 2015

The trade-off between welfare and equality in a public good experimentJournal articleAgathe Rouaix, Charles Figuières et Marc Willinger, Social Choice and Welfare, Volume 45, Issue 3, pp. 601-623, 2015

We report the results of an experiment on voluntary contributions to a public good in which we implement a redistribution of the group endowment among group members in a lump sum manner. We study the impact of redistribution on group contribution, on individuals’ contributions according to their endowment and on welfare. Our experimental results show that welfare increases when equality is broken, as predicted by theory (Itaya et al. in, Econ Lett 57:289–296, 1997 ), because the larger contribution of the rich subjects overcompensates the lower contribution of the poor subjects. However, our data suggest that the adjustment of individual contributions after redistribution is not always compatible with the predictions. In particular, subjects who become poor contribute much less than subjects who were poor since the beginning. Copyright Springer-Verlag Berlin Heidelberg 2015

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.