Non-uniqueness through duality in the von Neumann growth models

Duality can be viewed as the soul of each von Neumann growth model. This is not at all surprising because von Neumann (1955), a mathematical genius, extensively studied quantum mechanics which involves a “dual nature” (electromagnetic waves and discrete corpuscules or light quanta). This may have had some influence on developing his own economic duality concept. The main object of this paper is to restore the spirit of economic duality in the investigations of the multiple von Neumann equilibria. By means of the (ir)reducibility taxonomy in Móczár (1995) the author transforms the primal canonical decomposition given by Bromek (1974) in the von Neumann growth model into the synergistic primal and dual canonical decomposition. This enables us to obtain all the information about the steadily maintainable states of growth sustained by the compatible price-constellations at each distinct expansion factor.

Reducible von Neumann models and uniqueness

This paper can be regarded as a result of basic research on the technological characteristics of the von Neumann models and their consequences. It introduces a new taxonomy of reducible technologies, explores their key distinguishing features, and specifies which ones ensure the uniqueness of von Neumann equilibrium. A comprehensive comparison is also given between the familiar (in)decomposability ideas and the reducibility concepts suggested here. All these are carried out with a modern approach. Simultaneously, the reader may also acquire a complete picture of and guidance on the fundamental von Neumann models here.

A tranzakciós költségek elmélete és a társadalmi csereelmélet hatásai a bizalomra az ellátási láncban (Affects of Transaction cost and Social Exchange Constructs on trust In supply chain relationship)

A szerzők alapvető feltételezése, hogy az ellátási láncban a bizalom ösztönzi a felek közötti elkötelezettséget. Továbbá a bizalom növeli annak a lehetőségét, hogy az ellátási lánc sikeresen működjön. Ugyanakkor, a felek közötti bizalom hiánya gyakran megnöveli a tranzakciós költségeket, és így csökkenti a hatékonyságot. A cikkben bemutatott kutatás adatgyűjtésére több országban – Franciaországban, Magyarországon, Dél-Koreában, Tunéziában és az Egyesült Államokban – került sor. Összesen 729 érvényes kérdőív érkezett vissza, amelyeket a különböző ellátási láncok résztvevői töltöttek ki. A kutatási eredmények szerint az ellátási láncokon belüli üzleti kapcsolatokban a tranzakciós költségek elméletének összetevői (kapcsolatspecifikusság és viselkedési bizonytalanság), valamint a társadalmi csereelmélet tényezői (lecserélhetőség, észlelt megelégedettség, a partner hírneve és észlelt konfliktus) szoros kapcsolatban állnak a bizalom és az elkötelezettség változóival. _____ This article is based on the assumption that trust promotes commitment between partners in the supply chain and improves the chances of return on supply chain success. In contrast, a lack of trust between them often increases transaction costs and results in inefficiency. The results of this research, based on multi-country surveys with 729 returns from France, Hungary, Korea, Tunisia and the United States on supply chain professionals, reveals a strong affect of transaction cost constructs (TCC) (asset specificity and behavioral uncertainty) and social exchange constructs (SEC) (replaceability, perceived satisfaction, partner reputation, and perceived conflict) on trust-commitment variables in partnership based supply chain relationships. This paper employed a structural equation model to extract information from the survey data. Among the findings, the research indicates that a firm’s trustcommitment in dealing with their supply chain partnership is highly associated with not only transaction cost, but more so with social exchange variables. This study may open a new research avenue in that there is another construct, SEC, beside TSC that influences the degree of trust and commitment.

Climate change and freshwater zooplankton: what does it boil down to?

Recently, major advances in the climate–zooplankton interface have been made some of which appeared to receive much attention in a broader audience of ecologists as well. In contrast to the marine realm, however, we still lack a more holistic summary of recent knowledge in freshwater. We discuss climate change-related variation in physical and biological attributes of lakes and running waters, high-order ecological functions, and subsequent alteration in zooplankton abundance, phenology, distribution, body size, community structure, life history parameters, and behavior by focusing on community level responses. The adequacy of large-scale climatic indices in ecology has received considerable support and provided a framework for the interpretation of community and species level responses in freshwater zooplankton. Modeling perspectives deserve particular consideration, since this promising stream of ecology is of particular applicability in climate change research owing to the inherently predictive nature of this field. In the future, ecologists should expand their research on species beyond daphnids, should address questions as to how different intrinsic and extrinsic drivers interact, should move beyond correlative approaches toward more mechanistic explanations, and last but not least, should facilitate transfer of biological data both across space and time.