Effects of diet changes on market equilibrium, value sharing, public health, environment and land use. – DIETPLUS

Applied microeconomics combined with food science/engineering are used for analyzing various markets adjustments and possible improvements in supply chains. Econometrics works, experimental economics, industrial analyses lead to quantified estimates of various markets adjustments coming from these changes in diets.

This summary considers the 17 published articles listed on the HAL INRAE website. Some of these papers were published in a special issue on the Economics and Sociology of the Food-Health-Environment Nexus (Marette, 2020).

First, regarding diets, Marette and Réquillart (2020) show how economic models are useful to analyze trade-offs between various objectives defining a sustainable food system. Moreover, de Gavelle et al. (2020) examine the transition towards a lower consumption of animal proteins. Orset and Monnier (2020) consider the role of non-governmental organizations for influencing dietary behaviors.

Second, regarding the challenges related to meat, Jayet et al. (2020) show that animal feed and grassland use are key factors in the reduction of greenhouse gas emissions. Lambotte et al. (2021) show how direct and indirect land use changes modify the carbon footprint of dairy farms. Marette et al. (2021) underline consumers’ interest in antioxidant-enriched hams reducing colorectal cancer risks.

Third, some papers focus on the consumers’ acceptability of new foods, such as sausages based on vegetable proteins (Martin et al. 2021), new fermented “cheeses” mixing animal and plant protein sources (Saint-Eve et al., 2021), or new apples based on gene editing (Marette et al., 2021). It is shown that only a minority of consumers are ready to purchase these new products.

Fourth, some contributions deal with regulatory options for reaching a sustainable diet. Yokessa and Marette (2019a), Lambotte et al. (2020), Saïdi et al (2020), Wu and Marette (2020) and Marette (2021) study advantages and limits coming from various quality labels influencing behaviors. Yokessa and Marette (2019b) underline possibilities of taxes depending on greenhouse gas emissions and consumers preferences.

Eventually, all these contributions show that diets changes are possible but economically costly to implement.

By complementing diets models, economic approaches are useful for detailing incentives and prices adjustments that are essential for understanding behaviors and designing policies. We underlined possibilities and limitations regarding modifications in dietary regimes, when economic incentives and price adjustments are considered in models. We have shown that diets changes are possible but economically costly to implement. Economic modelling is particularly important for understanding social consequences of transitions towards sustainable food systems. Although economic models are imperfect, these models are useful for being upfront with the impact of regulatory tools on market adjustments and agents’ surpluses/benefits. The economic methodology of this project should be applied to various contexts. Economic evaluations should be emphasized and taken into account in political agendas of international institutions, such as the FAO, the WHO or the World Bank for making sustainable food systems acceptable by many actors.

17 published articles listed on the HAL INRAE website with the request “dietplus” (https://hal.inrae.fr/search/index/?q=dietplus, May 2021).

7 working papers

The Diet+ project proposes to analyse diets in France, by focusing on the relationships between the market mechanisms and the overall quality of diet, including the quality of the consumption, the possible improvements in the foods quality, the quality of the environment, the land use, and the possible improvements in public health. This project will particularly study the impact of diets changes on consumers, supply chains and farmers. These diets changes may come from both food innovations and/or policies aiming at improving both environment and public health. Applied microeconomics combined with food science/engineering will be used for analysing various markets adjustments and possible improvements in supply chains. Econometrics works, experimental economics, industrial analyses will lead to quantified estimates of various markets adjustments coming from these changes in diets. The objective of Diet+ is to provide precise estimates of impacts of diets changes on consumers, supply chains and farmers, by also considering both environment and public health.

The project will be divided in three Work Packages (WP) taking into account various markets adjustments from the land use to the consumers’ health. The WP1 will focus on some changes in diets and their influences on markets and supply chains. The WP2 will detail the foods variety offered to consumers and the foods innovations with their impacts on market structures. Based on results of WP1 and WP2, the WP3 will examine the optimal policy that could improve the overall quality of diets.

More precisely, the WP1 will focus on the overall change in diet, and its impact on both supply chains and characteristics related to environment and public health. We will focus on the meat sector that is often in front line regarding scientific and public debates. First, we will assess how a change in the demand for meat would impact overall consumers diet and agricultural production, by linking a demand model with an agricultural production model, assuming no food industry reactions. Second, we will study how this change in the demand for meat would influence consumers’ diet, firms’ profits and market shares of supply chains, by linking a demand model with a supply model for meat, assuming no agricultural producers’ responses.

The WP2 will study recent consumption trends regarding food variety and innovation. The first task will focus on animal products with healthy and environmental-friendly characteristics, including the new-vegetal substitutes for meat. The second task will analyse the relationship between the market structure, the level of health and environmental-friendly varieties, and the innovations. We also plan to determine how the health and environmental-friendly characteristics affect the value sharing between producers, manufacturers and retailers. The third task is devoted to design one innovation in the cheese sector, by creating a mixed “animal-vegetal” cheese and by evaluating its consumers’ acceptance.

The WP3 will analyse impacts of policies on diets, environment, public health, and their consequences on adjustments in supply chains. We will study the optimal choice of instruments such as per-unit taxes/subsidies, labels and/or standards/norms related to meat and dairy products. We will measure the impact of these policies on agents’ surpluses, environment and public health. Additionally, we will pay attention to the transition from the current agro-food sector to a new model aligned with nutrition and low-carbon objectives, which requires a precise study of “progressive” shifts at each stage of the supply chain. Eventually, WP3 will examine the complementarity between health and environment in the analysis of future policy choices.

The combination of these different approaches will give a complete view regarding sustainable policies that directly or indirectly influences behaviours, market mechanisms and sustainability of diets.