The efficiency of remanufacturing in a dynamic input–output model

For industrialised economy of ourdays, remanufacturing represents perhaps the largest unexploited resource and opportunity for realising a greater growth of the economy in an environmental-conscious manner. The aim of this paper is to investigate of the impact of remanufacturing in the economy from an economic-efficiency point of view. In static context this phenomenon was analysed in the literature. We use the multi-sector input–output framework in a dynamic context to study intra-period relationships of the sectors of economy. We extend the classical dynamic input–output model taking into consideration the activity of remanufacturing .We try to answer the question, whether the remanufacturing/reuse increases the growth possibility of an economy. We expose a sufficient condition concerning the effectivity of an economy with remanufacturing. By this evaluation we analyse a possible sustainable development of the economy on the basis of the product recovery management of industries.

Pairwise comparison matrices and the error-free property of the decision maker

Pairwise comparison is a popular assessment method either for deriving criteria-weights or for evaluating alternatives according to a given criterion. In real-world applications consistency of the comparisons rarely happens: intransitivity can occur. The aim of the paper is to discuss the relationship between the consistency of the decision maker—described with the error-free property—and the consistency of the pairwise comparison matrix (PCM). The concept of error-free matrix is used to demonstrate that consistency of the PCM is not a sufficient condition of the error-free property of the decision maker. Informed and uninformed decision makers are defined. In the first stage of an assessment method a consistent or near-consistent matrix should be achieved: detecting, measuring and improving consistency are part of any procedure with both types of decision makers. In the second stage additional information are needed to reveal the decision maker’s real preferences. Interactive questioning procedures are recommended to reach that goal.

A költségvetési korlát megkeményítése a posztszocialista országokban = Hardening of the budget constraint in the post-socialist countries

A költségvetési korlát megkeményítése nem egyforma mértékben ment végbe minden posztszocialista gazdaságban. Egyes országokban messzire jutottak ebben a tekintetben, másokban viszont alig változott az indulóállapot. A tanulmány áttekinti a költségvetési korlát puhaságának különböző megnyilvánulásait: az állami támogatásokat, a puha adózást, a nem teljesítő bankkölcsönöket, a vállalatközi tartozások felgyülemlését és a kifizetetlen béreket. A jelenséget sokféle tényező okozza, amelyek többnyire együttesen jelentkeznek. Az állami tulajdon fenntartása kedvez a puha költségvetési szindróma megrögződésének, a privatizálás elősegíti a keményítést, de nem elégséges feltétele a kemény korlát érvényesítésének. Ehhez megfelelő politikai, jogi és gazdasági környezetet kell céltudatosan kialakítani. A posztszocialista átmenet kezdetén sokan azt hitték, hogy a hatékony piacgazdaság létrehozásához elegendő lesz megvalósítani a liberalizáció, privatizáció és stabilizáció "szentháromságát". Mára már kiderült, hogy a költségvetési korlát megkeményítése az említett három feladattal egyenrangúan fontos. Ahol ez nem valósul meg (például Oroszország), ott a privatizáció nem hozza meg a várt eredményt. ___________________ The budget constraint has not hardened to equal degrees in the various post-socialist countries. In some of them, a great deal has been done in this respect, while in others there has been hardly any change from the initial state. This study surveys the typical manifestations of softness of the budget constraint, such as state subsidies, soft taxation, non-performing loans, the accumulation of trade arrears between firms, and the build-up of wage arrears. Softness of the budget constraint is caused by several factors that tend to act in combination. Thus retention of state ownership helps to preserve the soft budget-constraint syndrome, while privatization encourages the budget constraint to harden, although it does not form a sufficient condition for it to happen. Purposeful development of the requisite political, legal and economic conditions is also required. It was widely maintained at the outset of the post-socialist transition that the 'Holy Trinity' of liberalization, privatization and stabilization would suffice to produce an efficient market economy. Since then, it has become clear that hardening the budget constraint needs to be given equal priority with these. Otherwise, the effects of privatization will fall short of expectations, as they have in Russia, for example.

Measuring centrality by a generalization of degree

Network analysis has emerged as a key technique in communication studies, economics, geography, history and sociology, among others. A fundamental issue is how to identify key nodes in a network, for which purpose a number of centrality measures have been developed. This paper proposes a new parametric family of centrality measures called generalized degree. It is based on the idea that a relationship to a more interconnected node contributes to centrality in a greater extent than a connection to a less central one. Generalized degree improves on degree by redistributing its sum over the network with the consideration of the global structure. Application of the measure is supported by a set of basic properties. A sufficient condition is given for generalized degree to be rank monotonic, excluding counter-intuitive changes in the centrality ranking after certain modifications of the network. The measure has a graph interpretation and can be calculated iteratively. Generalized degree is recommended to apply besides degree since it preserves most favorable attributes of degree, but better reflects the role of the nodes in the network and has an increased ability to distinguish between their importance.

Distance-based accessibility indices

The paper attempts to develop a suitable accessibility index for networks where each link has a value such that a smaller number is preferred like distance, cost, or travel time. A measure called distance sum is characterized by three independent properties: anonymity, an appropriately chosen independence axiom, and dominance preservation, which requires that a node not far to any other is at least as accessible. We argue for the need of eliminating the independence property in certain applications. Therefore generalized distance sum, a family of accessibility indices, will be suggested. It is linear, considers the accessibility of vertices besides their distances and depends on a parameter in order to control its deviation from distance sum. Generalized distance sum is anonymous and satisfies dominance preservation if its parameter meets a sufficient condition. Two detailed examples demonstrate its ability to reflect the vulnerability of accessibility to link disruptions.