This presentation deals with some of the examples given in microeconomic textbooks. In textbooks, examples are primarily used for educational purposes : they can be used to present, explain or illustrate a concept, an assumption or a model. But the key role they play goes far beyond that. According to Kuhn, standard examples (the Greek word for ‘example' is ‘paradeigma') students read in scientific textbooks are an essential part of the process by which they not only absorb the significance and scope of theories, but also tacitly acquire a group-licensed way of looking at the world, so that differences in the nature and use of examples attest of the structure of scientific groups within the community.

In this presentation, we investigate the “impossible examples” taken in microeconomic textbooks. This terminology designates examples describing an « impossible world » (Jallais 2018), or examples which are, in fact, partly inconsistent with the very concept or hypothesis they exemplify. From a pedagogical point of view, unless they are unambiguously presented as being impossible, the use of this sort of example seems to be an aberration: a priori they cannot enable students to understand a concept or a hypothesis and even less its scope. This explains why we will investigate the rhetorics of impossible examples in the main microeconomics textbooks.

We will focus on the most renowned ones (best sellers, top 10 rankings...) like Mankiw's, Krugman & Wells's, McConnell, Brue & Flynn's, Cowen & Tabarrok's, Pindyck & Rubinfeld's, Varian's, for example.

We will more specifically examine the way(s) these « impossible examples » are presented. Are they used at specific moments in the presentation? Are these examples clearly presented as such? If so, how are they justified? What roles, if any, do these examples play in the introduction of the concepts and assumptions of the theory? What (possibly specific) message do they give?