Tom Bry-Chevalier’s thesis defense

Event details :

Thesis title: No Country for Old Meat? Economic and Environmental Stakes of Alternative Proteins

The jury is composed of:

• Mr Philippe Delacote, INRAE, BETA – Supervisor
• Mr Romain Espinosa, CNRS, CIRED – Supervisor
• Ms Ellen J. Van Loo, Purdue University – Rapporteure
• Ms Sabrina Teyssier, INRAE, GAEL, Grenoble – Rapporteure
• Ms Carine Barbier, CNRS, CIRED – Examiner
• Mr Jonathan McFadden, USDA – Examiner
• Ms Douadia Bougherara, INRAE, CEE-M  – Examiner
• Mr Bob Fischer, Texas State University – Examiner

Abstract: Transforming food systems is one of the great challenges of our time. Livestock farming uses 77% of agricultural land yet supplies only 18% of the calories and 37% of the protein people consume, and animal products account for a large share of the sector’s environmental impacts. The political, cultural, and behavioral levers that could reduce meat consumption, however, meet strong resistance. Alternative proteins have emerged as a possible answer, led by products designed to rival meat on taste, price, and convenience. Many of the promises associated with them, however, remain poorly substantiated. This thesis examines the validity of these promises and seeks to determine what economic analysis reveals about their actual contribution to the sustainability of the food system. Four chapters address this by drawing in turn on systematic reviews, experimental economics, a critical examination of environmental data and animal welfare modelling. The first chapter is based on a literature review that compares plant-based meat, cultured meat, single-cell proteins and insects across four dimensions: environmental impact, scalability, consumer acceptance and animal welfare. This synthesis of over 200 studies ranks plant-based meat as the most promising option. Single-cell proteins hold real potential, though this is tempered by uncertainties regarding large-scale production. Cultured meat could complement these sectors if it captures a distinct consumer segment, but technical and economic barriers remain. Insects, on the other hand, appear to be a sub-optimal solution across all dimensions. The second chapter critically examines the environmental data on insect farming, both for human consumption and for animal feed. It highlights that many studies are based on small, unrepresentative facilities and that reliable data remain scarce. Insect-based foods primarily replace low-impact plant-based products, rather than meat; in animal feed and pet food, due to the lack of genuine waste products as a substrate, their environmental impact exceeds that of conventional solutions. Their environmental benefits depend on several conditions being met, but these are rarely fulfilled. The third chapter examines product substitution through a discrete-choice experiment conducted amongst approximately 1,400 American adults. The products offered vary by species – beef or chicken – and by production method – conventional, plant-based or hybrid, the latter combining a plant-based matrix with a fraction of cultured cells. A mixed-logit model, expressed directly in terms of willingness to pay, captures individual preferences. Coupled with life-cycle assessment data, it enables an estimation of the net effect on emissions, depending on whether the hybrid products actually substitute for meat or primarily cannibalise plant-based alternatives, which are already low-emission. The fourth chapter models the net effects on animal welfare of a partial substitution of livestock farming with cultured meat. Using the AQALY (Animal Quality-Adjusted Life Year) framework, it introduces a ‘killing penalty’ – the ethical cost of slaughter – which is added to the deprivation of future welfare. Cultured meat improves animal welfare in almost all scenarios, except one: replacing mainly beef from low-intensity farming without taking the killing penalty into account, as these cattle on average have a long and positive life. This creates a tension between ethics and the environment: welfare gains are greatest when cultured meat replaces intensively reared chicken, whilst environmental gains are greatest when it replaces beef.