How do biological markets compare to the markets of economics?

After an introduction to biological markets written for non-biologists, I explore whether and to what extent natural markets, i.e. markets on which non-human traders exchange goods and services with members belonging to their own or to other species, can be compared to human ‘economic’ markets, i.e. the markets analysed by economists. Biological Market Theory (BMT) borrows jargon and ideas from economics, but was at least as much inspired by sexual selection theory, a collection of models of ‘mating markets’, including human mating markets. Here I ask two main questions: (1) Is there more than only a superficial resemblance between both types of markets? (2) Can the analysis of one yield insights about the other? First, I consider the different forms of human trading and markets and propose some biological ones to which these can best be compared, e.g. companies trading goods in markets shaped by ‘comparative advantage’ to underground nutrient exchange markets between plants and rhizobial bacteria and mycorrhizal fungi; job and retail markets with pollination, seed dispersal and protection markets between plants and insects; ‘embedded markets’ with grooming markets in non-human primates and so forth. Then I look at some phenomena that are considered to be exclusive to human markets, such as common currencies and binding contracts, and ask whether these are indeed that exclusive. Finally I look at the common ground: negotiations that take place on several types of markets, natural or not; the honesty of advertisements, which is recognised as a major problem for both human and non-human clients; the biological equivalent of the market – firm dichotomy and the importance of the costs of partner choice, which are known to economists as ‘transaction costs’ and to sexual selection theoreticians as ‘search costs’. I conclude that there are several good reasons to have a closer look at those properties that set human and biological markets apart, but certainly also at those features that make them comparable to each other.