### Article

## Proportionality, equality, and duality in bankruptcy problems with nontransferable utility

This paper studies bankruptcy problems with nontransferable utility as a generalization of bankruptcy problems with monetary estate and claims. Following the theory on TU-bankruptcy, we introduce a duality notion for NTU-bankruptcy rules and derive several axiomatic characterizations of the proportional rule and the constrained relative equal awards rule.

In the present paper the game theory is applied to an important open question in economics: providing microfoundations for often-used types of production function. Simple differential games of bargaining are proposed to model a behavior of workers and capital-owners in processes of formation of a set of admissible factor prices or participants’ weights (moral-ethical assessments). These games result, correspondingly, in a factor price curve and a weight curve – structures dual to production function. Ultimately, under constant bargaining powers of the participants, the Cobb-Douglas production function is received.

We understand a solution of a cooperative TU-game as the α-prenucleoli set, *α* ∈ *R*, which is a generalization of the notion of the [0, 1]-prenucleolus. We show that the set of all *α*-nucleoli takes into account the constructive power with the weight *α* and the blocking power with the weight (1 − *α*) for all possible values of the parameter *α*. The further generalization of the solution by introducing two independent parameters makes no sense. We prove that the set of all *α*-prenucleoli satisfies properties of duality and independence with respect to the excess arrangement. For the considered solution we extend the covariance propertywith respect to strategically equivalent transformations.

We consider a monopolistic firm that sells seasonal goods. The firm seeks the minimum of the total advertising expenditure during the selling period, given that some previously defined levels of goodwill and sales have to be reached at the end of the period. The only control allowed is on advertising while goodwill and sales levels are considered as state variables. More precisely we consider a linear optimal control problem for which the general position condition does not hold so that the application of Pontryagin's Maximum Principle may not be useful to determine a solution. Therefore the dual of the problem is studied and solved. Moreover, a necessary and sufficient condition for the feasibility of the primal problem is determined.

Human nature’s complexity and contradictoriness, accentuating the enigmatic essence of the Russian mentality, receives a unique depiction in Dostoevsky’s works. Often we read about strange specimens, whose thoughts and actions would bear typical features of Russian culture. The article sets out to examine these features: in particular, duality and a combination of mutually excluding qualities. In focus is violence committed by Dostoevsky’s characters, which inexplicably shifts from self-inflicted injuries to targeting of the outside world. The author suggests that it is caused by the character’s being torn between two conflicting urges, that eventually gives rise to duality. Thus, the character plays both roles: that of God and that of the master. These divine and sovereign characteristics can be measured through a discourse of pain, through perpetration of experimental violence.

We characterize the graphs whose induced subgraphs all have the following property: The maximum number of induced 4-paths is equal to the minimum cardinality of the set of vertices such that every induced 4-path contains at least one of them. In this chapter we describe all such graphs obtained from simple cycles by replacing some vertices with cographs.

A new approach is proposed revealing duality relations between a physical side of economy (resources and technologies) and its institutional side (institutional relationsd between social groups). Production function is modeled not as a primal object but rather as a secondary one defined in a dual way by the institutional side. Differential games of bargaining are proposed to model a behavior of workers and capitalists in process of prices or weights formation. These games result, correspondingly, in a price curve and in a weight curve - structures dual to a production function. Ultimately, under constant bargaining powers of the participants, the Cobb-Douglas production function is generated.

A model for organizing cargo transportation between two node stations connected by a railway line which contains a certain number of intermediate stations is considered. The movement of cargo is in one direction. Such a situation may occur, for example, if one of the node stations is located in a region which produce raw material for manufacturing industry located in another region, and there is another node station. The organization of freight traﬃc is performed by means of a number of technologies. These technologies determine the rules for taking on cargo at the initial node station, the rules of interaction between neighboring stations, as well as the rule of distribution of cargo to the ﬁnal node stations. The process of cargo transportation is followed by the set rule of control. For such a model, one must determine possible modes of cargo transportation and describe their properties. This model is described by a ﬁnite-dimensional system of diﬀerential equations with nonlocal linear restrictions. The class of the solution satisfying nonlocal linear restrictions is extremely narrow. It results in the need for the “correct” extension of solutions of a system of diﬀerential equations to a class of quasi-solutions having the distinctive feature of gaps in a countable number of points. It was possible numerically using the Runge–Kutta method of the fourth order to build these quasi-solutions and determine their rate of growth. Let us note that in the technical plan the main complexity consisted in obtaining quasi-solutions satisfying the nonlocal linear restrictions. Furthermore, we investigated the dependence of quasi-solutions and, in particular, sizes of gaps (jumps) of solutions on a number of parameters of the model characterizing a rule of control, technologies for transportation of cargo and intensity of giving of cargo on a node station.