Vol 80, No 4 (2025)

The paper is devoted to the presentation of the basic concepts and results of the theory of stable contract systems. This theory originated in 1962 and has significantly been developed since then. The main results (existence, polarization, latticing) were obtained in a bipartite situation, when contracting agents are divided into two groups, and contracts are concluded between agents from opposite groups. Another important limitation is that the agents' preferences are described by so-called Plott choice functions. The first part of the paper is devoted to this concept, which generalizes the concept of partial order. The second part sets out the theory of stable contracts itself.

We present a survey of various application of the method of the description of approximating distribution by means of differential equations for characteristic functions and, in particular, of applications of this description to estimates for the closeness of distributions. This idea was originally put forward by the author in 1976. Subsequently, this approach, which is called the Stein–Tikhomirov method by some authors (for instance, see papers by Eichelsbacher, Rednoss, Sunklodas, and Formanov), was significantly developed.