“Walrasian Equilibrium Behavior in Nature”, 2021-07-06 (; similar):
Mutualisms are commonly observed ecological interactions, often involving the exchange of resources across species. Such exchanges can be thought of as biological markets. Biologists modeling these markets often employ an informal mix of economics and game-theoretic concepts. A fundamental question is whether exchange in biological markets is consistent with general economic equilibrium theory (GET), the main paradigm used to study exchange in economics. This paper uses data from biological experiments to demonstrate that the trading behavior of mycorrhizal fungi is consistent with the predictions of GET. The large volume of knowledge in GET might result in new insights about biological exchange. In turn, experimental findings in biology can lead to a new field of application for GET.
The interaction between land plants and mycorrhizal fungi (MF) forms perhaps the world’s most prevalent biological market. Most plants participate in such markets, in which MF collect nutrients from the soil and trade them with host plants in exchange for carbon.
In a recent study, et al 2019 conducted experiments that allowed them to quantify the behavior of arbuscular MF when trading phosphorus with their host roots. Their experimental techniques enabled the researchers to infer the quantities traded under multiple scenarios involving different amounts of phosphorus resources initially held by different MF patches.
We use these observations to confirm a revealed preference hypothesis, which characterizes behavior in Walrasian equilibrium, a centerpiece of general economic equilibrium theory.
[Keywords: Walrasian behavior, biological markets, revealed preference]