Séminaire du pôle observation, données et méthodes

L’océan est une source de richesses mais il est aussi un espace sujet à des pressions et des conflits d’usages pour satisfaire les différents besoins de la société. Trois problématiques sont retenus dans ce séminaire pour mettre en évidence l’intérêt de deux méthodes d’évaluation non marchande. La première est fondée sur des mécanismes de déclaration des préférences qui consistent à mettre l’usager face à plusieurs choix (expérimentaux) entre plusieurs scenarii fondés sur un véhicule de paiement (cf. la première présentation). La seconde méthode est celle des prix hédoniques permettant de déduire grâce à des mécanismes de révélation des préférences, la valeur d’un bien non-marchand à partir des variations des prix d’un bien marchand (cf. les deux autres présentations).

PROGRAMME

1. Kourantidou M. “Non-market valuation of marine invasive species: methods and survey design”
2. Binet M-E et al. “Economic value of nutritional and environmental attributes of seafood: evidence from the canned sardine market”
3. Nassiri A. & Nassiri N. “Do offshore wind farms lead to a depreciation of real estate assets?”

14h30 > 15h – Speaker: M. KOURANTIDOU

“NON-MARKET VALUATION OF MARINE INVASIVE SPECIES: METHODS AND SURVEY DESIGN” KOURANTIDOU M.

Marine invasive species pose complex environmental and socio-economic challenges.  Effective management requires prioritizing which species to target and determining the intensity of intervention needed to limit their spread. This example presents results from a choice experiment designed to estimate the Norwegian population’s willingness-to-pay (WTP) for reducing the spread of the invasive Red King Crab (RKC) in the Barents Sea. The analysis explores how WTP changes when management of this species is considered in isolation versus within the broader context of managing multiple invasive species in Norway. Results show that reminding respondents that the valuation concerns a specific species (RKC) reduces WTP for the attribute describing reduced spread, suggesting that such “embedding reminders” can help mitigate embedding effects in non-market valuation studies.

Building on this approach, ongoing work explores how similar valuation frameworks can be applied to emerging management challenges associated with the spread of Pacific oysters in Nordic coastal ecosystems, with the aim of better understanding how coastal users and the wider public value different management strategies such as containment, control, or adaptation.

Keywords : Marine invasive species; non-market valuation; stated preference methods; discrete choice experiments; willingness to pay; environmental management & policy

15h00 > 15h30 – Speaker: M-E BINET

“ECONOMIC VALUE OF NUTRITIONAL AND ENVIRONMENTAL ATTRIBUTES OF SEAFOOD: EVIDENCE FROM THE CANNED SARDINE MARKET” M-E BINET, F. DAURES, F. ALBAN, E. CHOBERT, M. MERZEREAUD

We examine the value of health attributes (including omega-3) and ecolabels (sustainable fishing practices, organic ingredients) in the French canned sardine market by comparing both supply and demand sides using two datasets, one comprising 1,309 tins and the second including 587 home consuming sardine consumers. A hedonic price model is estimated, with product characteristics conceptualised as food values (FVs). Contrary to prior research showing that health attributes increase willingness to pay (WTP) for fresh fish, our results indicate that omega-3 FV is associated with lower sardine tin prices. Conversely, ecolabels are positively valued, consistent with previous empirical evidence. Our findings also reveal a market characterized by a high degree of heterogeneity in product differentiation strategies, aimed at addressing the full spectrum of consumer preferences with respect to price and labeling. These results underscore the specificity of canned fish as a credence good within a highly segmented market structure.

Keywords: Food values, Differentiation, Health attributes, Labels, Omega3, Hedonic prices, Multiple correspondance analysis, Sardine tins,

15h30 > 16h – Speaker: A. NASSIRI

“DO OFFSHORE WIND FARMS LEAD TO A DEPRECIATION OF REAL ESTATE ASSETS?” A NASSIRI & N. Nassiri

We assess these concerns by analyzing changes in the real estate market in the vicinity of the first French offshore wind farm, built off the coast of Saint-Nazaire between 2020 and 2022. Our analysis relies on a difference-in-differences hedonic price model developed from a critical review of around forty studies. This model accounts for several determinants of real estate price formation: neighborhood effects related to multiple amenities and disamenities; spatial autocorrelation effects among neighboring transaction prices; information asymmetries between buyers and sellers; and a broad set of control variables capturing housing heterogeneity, characteristics of occupants, and changes across several sectors of the local economy. The specification of the model is flexible, as it allows for the interdependence among these determinants through a translogarithmic functional form.

After conducting several robustness tests, our estimates show no statistically significant effect of the wind farm on real estate prices after the beginning of its construction, for either houses or apartments. The results also reveal a decline that the housing market for houses (only) anticipated as early as the beginning of the public debate, which gradually faded once construction work began. This temporary decrease in house prices ranges from –1.8% to –7.7% depending on the area, particularly closer to the coastline. Apartments do not experience any decline; in some locations they even record an increase (up to +5%). These findings, together with the various sensitivity analyses conducted, indicate that despite the concerns expressed during the field survey, there has been no depreciation of real estate assets in the coastal municipalities facing the Saint-Nazaire offshore wind farm after its construction.

Keywords: Difference-in-differences hedonic pricing; Offshore wind farm impacts; Wind turbine proximity and visibility; Information asymmetry; Spatial autocorrelation; Covisibility; Amenities and disamenities.