佐々木 康朗

This paper discusses rationalizable self-confirming equilibrium (RSCE) in static games with unawareness that captures steady states of such games. We begin by defining the equilibrium concept in terms of its epistemic conditions. k-RSCE is a situation in which agents make rational choices and have correct beliefs about one another’s choices, and moreover these can be mutual belief to the k-th order. We then present an alternative definition that dispenses with these epistemic conditions and allows us to obtain equilibria through iterative eliminations of certain action profiles. In standard static games, k-RSCE reduces to Nash equilibrium, but not under unawareness. We examine the equilibrium concept’s properties and clarify its relationships with other equilibrium concepts for games with unawareness.

In recent years, technology firms have been facing a highly competitive environment on a global scale. The firms are accelerating to establish R&D sites abroad in order to access global knowledge resources. In this context, global R&D projects have become more complex and R&D bridge managers (BMs), who facilitate global research collaboration, play a pivotal role here. This study aims to investigate the difficulties that BMs are facing and to explore the roles of BMs in global R&D projects. We interviewed nine BMs who have facilitated global R&D projects and propose a model depicting four common and critical difficulties present in facilitating research collaboration between teams in the home country and foreign R&D teams. The unique contribution of this paper focuses on the individual managerial level, while most previous studies on global R&D mainly focused on an organizational level.

© 2019 PICMET. Although globalization provides opportunities for companies to expand their businesses, it brings more challenges to global project management. Collaboration in global research and development (RD) projects requires competent individuals helping to improve project success. There are liaisons who we call RD bridge managers (BMs). They facilitate research collaboration in global RD projects between teams in the home country and the firm's foreign RD teams. Success in BM role requires a set of competencies that related to this job. Competency development frameworks have proofed themselves to be an effective tool for human resource management. The frameworks identify skills, behaviors, and knowledge that are necessary to ensure job performance. The frameworks have three components: competency list, competency assessment, and competency development method. This study aims to propose a competency list for BMs. This competency list is one component of BM competency development framework (BMCDF). The competency list is constructed based on literature survey. It may help BMs to overcome difficulties and challenges in their job. The BMCDF could benefit both BMs to plan for their competency development and organizations to clarify expected job performance. This competency list will be used in the future as part of BMCDF for facilitating global RD projects.

© 2018, Springer-Verlag GmbH Germany, part of Springer Nature. We define rationalizability for multicriteria games and examine its properties. In a multicriteria game, each agent can have multiple decision criteria and thus has a vector-valued utility function. An agent’s rationalizable action is defined as such an action that can survive iterated elimination of never-Pareto optimal actions. We first generalize some properties of standard rationalizability such as existence to the multicriteria case. We then show that a rationalizable action in some weighted game is also rationalizable in the original multicriteria game, whereas the converse may not hold. This implies the robustness of non-rationalizable actions under utility aggregations for any weight vectors. We also discuss interpretations of mixed actions and their implications to multicriteria games.

© 2018 Portland International Conference on Management of Engineering and Technology, Inc. (PICMET). Since we live immersed in organizational systems, understanding the set of competencies that are required for individuals to behave successfully in such systems is of primordial importance. The concept of systems intelligence (SI), developed in the field of systems thinking, puts forth a set of competencies in such settings. The relationship between SI and knowledge management has already been discussed conceptually in a previous study, particularly in the context of the SECI model, a well-known framework of organizational knowledge creation (KC). The present study is the first attempt to provide empirical evidence on the relationship between these two constructs, namely SI and KC. By means of a questionnaire survey using established scales, we collected data from employees of various organizations. We then investigated statistically how each SI competency can affect each KC process. The results show that, among several SI competencies, both a spirit of discovery and positive engagement have the most predominant influence on diverse KC activities in organizations. These findings could be helpful for managers to design mechanisms to involve people in KC activities in their groups or organizations.

© 2017 IEEE. This paper provides a game theoretical characterization of information supervisory control problems. Information supervisory control deals with indirect control of human behavior by controlling information distribution. For an arbitrary game, we consider an agent outside the game called a supervisor. It can provide the players with information about the game, which results in change in their information structures and hence possible outcomes. The supervisor's controllability is defined as its ability to achieve the players' behaviors as intended. We present a general model and then analyze its particular class which we call state-dependent team collaborations. We discuss the possibility of information supervisor as a decision support system in such situations.

© 2016, Springer Science+Business Media New York. In game theory, recently models and solution concepts of games with unawareness have been developed. Focusing on static games with unawareness, this paper discusses generalized Nash equilibrium, an existing equilibrium concept. Some generalized Nash equilibria can be unstable in the sense that, once an equilibrium is played, some agent’s belief is falsified at some level of someone’s perception hierarchy. Based on the observation, we characterize a particular class of generalized Nash equilibrium that expresses stable belief hierarchies so that it can avoid such a problem. This class of equilibrium can be motivated as a stable convention of the game. We also study how unawareness can affect the agents’ behaviors in a stationary state.

© 2016 Portland International Conference on Management of Engineering and Technology, Inc. Effective technology marketing that extracts potential needs from customers and matches them with a manufacturer's core technology seeds is very important in the current global, competitive market. Several methods have been proposed to extract these needs, including rapid prototyping, agile development, and design thinking. However, it is sometimes difficult to apply these methods in Business-to-Business (B2B) products such as industrial machinery because customer needs are complicated and context-dependent. 'Virtual catalogs' (imaginary catalogs for future products) have been used by several B2B companies. Using virtual catalogs, product designers can specify their images of future products and use them to extract potential needs from customers. Although several procedures to construct virtual catalogs have been established, the methods for using these catalogs have not been scientifically investigated, and the effectiveness of their utilization depends on individual communication skills. This paper proposes an effective method of utilizing virtual catalogs and verifies the effectiveness by a laboratory experiment as a role-play test of technology marketing using virtual catalogs.

© 2017, © Emerald Publishing Limited. Purpose: This paper aims to show that systems intelligence (SI) can be a useful perspective in knowledge management, particularly in the context of the socialization, externalization, combination and internalization (SECI) model. SI is a recently developed systemic concept, a certain kind of human intelligence based on a systems thinking perspective. Design/methodology/approach: This paper first provides an overview of the related literature, and then conceptually discusses the role of SI in organizational knowledge creations. Findings: SI can work as a powerful momentum in each stage as well as the whole process of SECI. Originality/value: This paper is the first application of SI to the field of knowledge management. It provides us with a new perspective to touch human factors in knowledge management processes, which are considered to be essential in the SECI model.

© 2016 Elsevier B.V. We conduct a simulation analysis to see the trade-off between employing serial dictatorship and reducing unmatched children in nursery school choices. It is motivated by a social problem in Japan: there are a large number of children who wish to get into nursery schools but stay unmatched, while serial dictatorship is widely used.

© 2016 World Scientific Publishing Company. Recently models and solution concepts of games with unawareness have been developed. This paper discusses the issue of reducing static games with unawareness to standard Bayesian games and shows that equilibrium concepts for the two formulations, i.e., generalized Nash equilibrium and Bayesian equilibrium, are equivalent. We discuss implications of the result.

© 2016, Institute of Systems Science, Academy of Mathematics and Systems Science, CAS and Springer-Verlag Berlin Heidelberg. This paper discusses the relationship of two independently developed models of games with incomplete information, hierarchical hypergames and Bayesian games. It can be considered as a generalization of the previous study on the theoretical comparison of simple hypergames and Bayesian games (Sasaki and Kijima, 2012) by taking into account hierarchy of perceptions, i.e., an agent’s perception about the other agents’ perceptions, and so on. The authors first introduce the general way of transformation of any hierarchical hypergames into corresponding Bayesian games, which was called as the Bayesian representation of hierarchical hypergames. The authors then show that some equilibrium concepts for hierarchical hypergames can be associated with those for Bayesian games and discuss implications of the results.

© 2015, International Society for the Systems Sciences (ISSS). All rights reserved. This paper presents a game theoretical framework to analyze the possibility of knowledge transfer about a game structure. We study, under asymmetric awareness of two agents in a game, what kind of knowledge can, or cannot, be transferred from one agent who has more knowledge to the other agent with restricted knowledge prior to playing the game. Such situations are generally characterized as a particular class of a recently developed framework of extensive-form games with unawareness and analyzed with the solution concept called rationalizability. We show some properties of such games and example analysis. Also we discuss some ideas to incorporate, in a more general way, inferences of the agents about knowledge transfer under asymmetric awareness.

© Springer International Publishing Switzerland 2015. In game theory, recently models and solution concepts of games with unawareness have been developed. This paper focuses on static games with unawareness and points out a conceptual problem of an existing equilibrium concept called generalized Nash equilibrium. Some generalized Nash equilibria can be cognitively unstable in the sense that, once such an equilibrium is played, some agent may feel that the outcome is unexpected one at some level of someone's perception hierarchy. This may lead to change in the agent's perception and thus her behavior. Based on the observation, we characterize a class of generalized Nash equilibrium that satisfies cognitive stability so that it can avoid such a problem. Then we discuss relationships between cognitively sable generalized Nash equilibrium and Nash equilibrium of the objective game, that is, how unawareness can or cannot change the equilibrium convention.

& Sons, Ltd. We discuss linkages between hypergame theory and systems intelligence and examine how both perspectives can benefit one another. We argue that hypergame theory can provide a formal foundation for key premises of systems intelligence, whereas the philosophy of systems intelligence can present a new way to illustrate hypergame theory as a perspective in order for an agent acting inside a system to become systems intelligent. The integrated perspective elaborated here is particularly relevant in the context of certain kinds of paradoxical but ubiquitous human interactive situations called systems of holding back. © 2015 John Wiley

The present study focuses on two major types of fare collection systems for public transportations, barrier and barrier-free, and provides a mathematical framework to evaluate optimal choices between them, i.e., which system can be more profitable for a transit agency. In particular, we consider game-theoretic interactions between the transit agency and passengers for the barrier-free system and suppose that frequencies of free rides of passengers as well as inspections of the transit agency are given as a Nash equilibrium. Then the optimal choice of fare collection system is described as a subgame perfection solution in an extensive form game. We also conduct a comparative static analysis and examine how each parameter can affect the choice. As an application, we use the framework to explain various choices of fare collection systems in our society depending on local circumstances or transportation types. © 2013 Elsevier Ltd.

<p>本研究では，全国の詳細な地域分割に基づく交通データ及び需要予測モデルを構築する．これを用いて，現在の国土構造・交通体系のもとで効果的なCO₂排出削減を推進するための地域別削減割当てについて検討する．モデル分析では，自動車燃料課税の強化を想定して，CO₂削減効果を地域別に計測し，さらにその結果が全国の排出削減の総費用最小化を達成するという性質に着目して，経済効率的な地域別CO₂削減割当てを決定する一つの考え方を提示する．本分析の設定条件のもとでは，課税による1人あたりCO₂削減量は，都市部よりも地方部で大きくなるが，削減率でみると都市部の方が若干大きくなることが示された．</p>

本研究では，市区町村単位の空間的応用一般均衡（SCGE）モデルを用いて東日本大震災の経済被害を空間的に把握する．東日本大震災では津波の被害が大きく，被災地域において沿岸部と内陸部では被害の程度が大きく異なる．このことを反映した分析を行うため，全国を市区町村単位で2,342地域に分割し，地域間の財の輸送費用や移出入，所得移転を考慮したSCGEモデルを構築する．また，モデル構築に必要な経済データを，各種の既存統計に基づく推計により作成する．分析では，東日本大震災の影響として被災地域における企業の生産効率の低下を仮定して，経済被害の計測を行った．その結果，被災地域の沿岸部を中心に東北地方で大きく被害が出ていることに加えて，直接の被災地域ではない関東以西の工業地帯にまで被害が波及していることが示唆された．

A new solution concept for hypergames called subjective rationalizability is proposed. Hypergame theory is a game theoretical framework that deals with agents who may misperceive game structures and explicitly takes into account hierarchy of perceptions, that is, an agent's view about another agent's view and so on. An action of an agent is called subjectively rationalizable when the agent thinks it can be a best response to the other's choices, each of which the agent thinks each agent thinks is a best response to the other's choices, and so on. Then it is proved that subjective rationalizability is equivalent to the standard notion of rationalizability under a condition called inside common knowledge. The result makes the new solution concept a practical tool in hypergame analyses. Theoretically, it is characterized as such a concept that provides the precise implication, that is, predicted outcomes, of a given hypergame structure. © 2014 Yasuo Sasaki.

The present study discusses the relationships between two independently developed models of games with incomplete information, hypergames (Bennett, 1977) and Bayesian games (Harsanyi, 1967). The authors first show that any hypergame can naturally be reformulated in terms of Bayesian games in an unified way. The transformation procedure is called Bayesian representation of hypergame. The authors then prove that some equilibrium concepts defined for hypergames are in a sense equivalent to those for Bayesian games. Furthermore, the authors discuss carefully based on the proposed analysis how each model should be used according to the analyzer's purpose. © 2012 Institute of Systems Science, Academy of Mathematics and Systems Science, CAS and Springer-Verlag Berlin Heidelberg.

本稿では,相互意思決定状況を主観的に認識する主体を想定したハイパーゲーム理論を紹介する.通常のゲーム理論は,ゲームのルールが主体間で共有されている際の合理的な意思決定を追求するのに対し,ハイパーゲーム理論では,そもそもゲームの構造に関する認識に主体間で差異があるような状況を考え,そのことが主体の意思決定やゲームの結果に及ぼす影響について分析する.さらにゲームの結果の認識のあり方へのフィードバックについても扱い,認識と意思決定の相互関係を論じるものである.具体的な事例をもとにいくつかのハイパーゲームモデルを紹介しながら,その独自の問題意識について解説する.

We propose a new equilibrium concept in hypergames called systems intelligent equilibrium (SIeq). Hypergame theory is a game theoretical framework that deals with an agent who has each subjective internal view about a game situation and makes decisions based on it[3]. SIeq refines stable hyper Nash equilibrium[16] by considering some off-the-equilibrium plays. The main proposition suggests that it leads to Pareto-optimization from an objective viewpoint in hypergames satisfying some conditions. Practically and philosophically, the idea is inspired by the discourse of systems intelligence[7, 8]. We discuss the significance of systems intelligence in terms of hypergames and show some practical implications for agents acting inside a complex system. In particular we analyze paradoxical but ubiquitous social phenomena called systems of holding back. ©2010 IEEE.

The present paper tries to model how some kinds of misperceptions of agents are preserved in a decision making situation where multiple agents are involved. We use hypergame model which is a theoretical framework to deal with agents who may misperceive situations (Bennett et al., 1979). After each play of hypergame, agents may update their perceptions based on the result, that is, the structure of the hypergame may change. However, in some case, they may not, and the hypergame is 'stable', that is, their misperceptions are preserved. To discuss stability of hypergames, we newly define a solution concept what we call stable hyper Nash equilibrium. Using these ideas, we analyze the stability. To demonstrate change in perceptions of agents, we consider agent-based intrinsic motivation. Although we provide general foundation for discussion, we analyze a game called battle of sexes as an example case.

In this paper, we extend hypergame models by introducing mixed strategies and illustrate that the mixed extension enables us to deal with hypergames with cardinal utilities, while the literature has dealt only with hypergames with ordinal utilities. We then show some unique features of mixed-strategy equilibria of hypergames (hyper Nash equilibrium [4: Kijima, 1996]) and study the comparative statics of equilibria due to change in misperceptions about cardinal utilities. Finally, we examine these findings in the framework of inspection games [1: Avenhaus et al., 1996].