Since few decades already, one witnesses an extension of markets to domains where they were up to now absent. Understanding this dynamics of commodification requires to have an operational concept of market which goes beyond the simple intersection of supply and demand curves, and envision it as a complex institution. Almost a century ago, Marcel Mauss was qualifying an institution as a fait social total, meaning that it expresses itself in many different dimensions : economical, juridical, political, sociological, anthropological ones...

I wish to show in this paper that, in order to understand the extending market dynamics one observes, and following Mauss, one needs a pluridisciplinary approach to what a market is, and does.

I intend here to focus on the process of construction of a new, fictitious commodity (Karl Polanyi), by exploring how ecosystem services are currently being defined with the aim of allowing market exchange of these peculiar objects. The definition of a commodity entails two processes. The first one is one of technical qualification, where ecosystem services are precisely defined, normalised and standardised, in order to be unambiguously measured and quantitatively compared. As such, market processes are embedded in a more global context of calculus and rationalisation in the Weberian sense.

In the case of ecosystem services, defining measures depends of course upon the object. For instance, in the case of genes, and lively organisms which are more and more considered in their genetic dimension, the measure is intended to grasp the specificity of their genetic code, analysed as bits of information. In the case of forests, what will be measured is their capacity to absorb CO2, which is a function of the volume of biomass concerned. In these examples, economics has to discuss with ecology, biology and genetics : the understanding of the market process has to be pluridisciplinary.

The second process involved in the definition of a fictitious commodity is one of juridical qualification, mainly property rights. Ecosystem services are diverse, and so are regimes of property rights. In some cases, ecosystem services are attached to the land, and what are to be studied are land rights. When considering genes and lively organisms, as was said, they are defined in terms of genetic information : what matters here is the system of intellectual property rights in use. Understanding market phenomena from this perspective of property rights cannot be done without a thorough interaction with law, sociology and ethics.

My conclusion is thus twofold.

First, analysing market dynamics cannot be done without the help of other disciplines. Hence, in order to understandand contemporary market dynamics and their specificities, one has to build a truly transversal concept of what a market is.

Second, what such study shows in the case of ecosystem services is that one sees a new phenomenon of qualification of nature : in order for these new dimensions of nature to enter into the market sphere, the latter have to be redefined in a dematerialised way. Lively organisms are not considered from their phenotypic caracteristics but from their genotype only, i.e. in terms of information. Forest are not anymore defined as populations of trees but as « carbon sinks », as their reality only exists through their function of carbon sequestration. One could not have highlighted such a dematerialisation without the richer, pluridisciplinary concept of a market proposed here.