The paper, published in the journal Nature Food, said that when food spoilage was reduced, the amount of food available in markets increased, which in turn led to cheaper prices for the food.
“Let’s say the price of cereals goes down because of improvements in food system efficiency; now you can afford to eat the same amount more often,” said Margaret Hegwood, the paper’s lead author.
“Consumers respond to these price decreases, purchasing more than they had before, which offsets some of the benefits of reducing the food loss and waste.”
“The elimination of food loss and food waste has been promoted by scientists and advocates as a way to reduce adverse environmental impacts of food production,” added co-author Steven Davis.
“There is a sound basis for this reasoning: Loss and waste along the supply chain accounts for as much as a quarter of global food system greenhouse gas emissions and 6 percent of total emissions worldwide.”
The rebound effect
Of course, such a significant fall in food wastage should reduce greenhouse gas emissions. However, the laws of economics mean that everything isn’t that simple. With more food available, prices would fall and consumption would increase. This reduces hunger but changes supply and demand, meaning that between 52% and 71% of the possible food waste saved could be erased by the increased demand. This is known as the “rebound effect.”
This, in turn, would erase many of the environmental benefits, including reduced land use (as reduced food waste would cut down on the need for food production), as well as reduced water use and reduced carbon emissions themselves.
“Our model basically formalized Econ 101: Reducing food loss and waste shifts the supply and demand curves, respectively,” said Matt Burgess, one of the co-authors. “How sensitive supply and demand are to prices – which we get from previous research – then determines how much we project food prices and consumption will change.”
“There is a tension between the two objectives of eliminating food waste and increasing food security,” added Davis. “Improving supply chain efficiency and thereby lowering food costs could help make food more affordable in less-advantaged countries. But, especially in those places, we may need to adjust our expectations about the environmental benefits of avoiding waste and loss.”
So in essence, while the greater abundance of food would still reduce overall hunger levels, the increased demand would mean the benefits to the environment would be severely curtailed.
'Rebound effects could offset more than half of avoided food loss and waste ’
Published on: 20 July 2023
Authors: M. Hegwood, N. G. Burgess, E. M. Costigliolo, P. Smith, B. Bajželj, H. Saunders & S. J. Davis