Discrete-time Walrasian dynamics with myopia.

Summary The purpose of this thesis is to propose a theoretical framework inspired by the work on non-testing in the line of Smale (1976), Champsaur and Cornet (1990), Bottazzi (1994), Giraud (2010). Beyond the attempt to solve the problem of describing trade processes, it also aims to propose a macroeconomic model that explicitly takes into account the micro-structure of trade. It is composed of four chapters, the first of which is a reminder of the main works on non-trading, followed by a presentation of the approach that we propose to address the problem mentioned above. The last three chapters provide the details of the main results. These results are organized around three articles that mark the main stages of our research. The first article is devoted to the definition of a local economy with good properties that serve as a basis for the dynamics we want to define. This local economy is defined by the restriction of exchanges by means of a parameter "tau". The main property sought for this microstructure (the local economy) is the uniqueness of the equilibrium. We have shown that for sufficiently small "tau", the local economy admits a unique normalized equilibrium. In the second paper we have defined a discrete time dynamics by means of the local economy concept of the first paper. The main result is the convergence to a Pareto optimum in a finite number of steps. In the last paper we introduced money in the discrete time dynamics model by means of a cash constraint and a money market. We have drawn some interpretations in terms of monetary policy in the framework of our model.