Productivity Dynamics and the Role of ‘Big‐Box’ Entrants in Retailing

We use a dynamic model to measure the impact of the entry of large stores on incumbents’ productivity separate from demand while accounting for local markets and the endogeneity of entry. Using data on all retail food stores in Sweden, we find that incumbents’ productivity increases after the entry of large stores and that the magnitude of the increase declines toward the upper part of the productivity distribution. Our findings highlight that large entrants drive productivity.     

室温下具有“内置”机制的导电油墨自烧结研究

目前,尚没有金属油墨可以在室温下只通过印刷步骤便形成导电图案的技术。例如使用纳米金属油墨在塑料电子产品上印制导电图案,必须进行额外的烧结处理,通常是通过加热至高温来实现。在烧结过程中,形成图案的纳米粒子（NPs）发生团聚以形成连续的导电层。近年来,发展了很多新型的烧结工艺,如微波、激光烧结,脉冲氙气、电子或化学烧结以及等离子烧结等,但是这些方法通常需要高成本的设备以及复杂的预处理或后处理工艺。因此,对于油墨而言,尚需研究的课题是,印制后无须额外烧结工艺即可获得高导电率。     

Expressing multiagent coalition structure problems for optimisation by quantum annealing

ABSTRACT

This paper addresses the problem of finding the optimal coalition structure in a multiagent system by expressing it in a proper format that can be solved by an adiabatic quantum computer such as D-Wave. The general case with any number of agents and graphs of agent connections with arbitrary structure is considered, and a method to handle the issues that arise from mapping a weighted graph game with intersecting edges on the lattice of qubit cells is provided. A principled discussion about the parameter values and mathematical proofs for the design choices are also included.     

Similarity in the Restrictiveness of Bond Covenants

Abstract

We examine the economic determinants and consequences associated with the inclusion of covenants with similar levels of restrictiveness in bond contracts. Using a unique Moody’s bond covenant dataset, we develop measures that capture similarity in the restrictiveness of bond covenants relative to previously issued peer bonds. We document that the demand for similarity by issuers, their advisors and bond investors follows the predictions of sociological and economic theories. Further, consistent with similarity in covenants reducing bond investors’ information acquisition and processing costs, we show that bonds with more similar covenant restrictiveness receive lower yields at issuance. These bonds are also more likely to be held by long-term bond investors, such as insurance companies, and are characterized by greater liquidity in the secondary market, providing a partial explanation for the lower bond yields. Our results highlight the benefits of covenant similarity and suggest that the use of covenants with similar restrictiveness levels brings information acquisition and processing cost savings that may be larger than the monitoring benefits provided by covenants with more tailored features.     

Fair e-lottery system proposal based on anonymous signatures

The games in which large amount of money is involved are always called into question about the existence of the possibility to manipulate the game for an immediate benefit. Lottery system is not an exception in this regard; moreover, it is a subject of rumours that the game is not as fair as it is pretended to be. After studying the advantages and drawbacks of conventional lottery systems, the authors are proposing an e-lottery system based on anonymous signatures. Even though the proposal is using electronic signatures, which imply complex calculus and the possession of digital certificates for each player, the proposed system compensates these drawbacks by increasing trust and confidence of both the players and the lottery organizer. This will lead to more players participating in the lottery, which translates to more revenue for the lottery and larger prizes for the players.     

Performance Measure Aggregation in Multi‐Task Agencies

In multi‐task environments, the efficiency of aggregating managerial performance information and the degree of customization/standardization are closely related. Aggregation without information loss (i.e., statistically sufficient) requires at least as many measures as there are effective tasks (which arise through a task aggregation process analogous to that applied to homogeneous activities in activity‐based costing) and can be used uniformly for evaluation across similar jobs. Aggregation without economic loss (i.e., economically sufficient) can be achieved with a single performance measure but requires customization even across similar jobs. The main implication is that job complexity, the number of aggregate performance measures, and the degree of customization in performance measurement are interrelated. In particular, at the same level of performance measure aggregation, we predict highly customized performance evaluation in complex multi‐task jobs and standardized (uniform) performance evaluation only in simpler jobs with fewer tasks. We discuss additional empirical implications in the conclusion.     

Paediatric head injuries treated in a children's emergency department from Cluj-Napoca,Romania

The aim of the study was to describe paediatric head injuries and identify factors that led to advanced care. Incident cases of head injuries that sought care from December 2008 to October 2010 at Children's Emergency Hospital Cluj-Napoca were evaluated. The main outcome was transfer or admission to advanced care. From a total of 3053 children treated for an injury, 1541 (50.4%) presented with head injury. A total of 960 (62.3%) of the children with a head injury required advanced care treatment. Young children were more likely to suffer a head injury than older children, but a higher proportion of older children required advanced care (70.3%). Children who suffered a head injury as a consequence of road traffic were almost five times more likely to require advanced care (OR: 4.97; 3.09-8.06) than being released. Our results suggest that data on injuries provide evidence-based information on the nature of injuries children are prone to, and what activity, type, and mechanism of injury impact Romanian children.