Search results for "Transaction"
showing 10 items of 229 documents
Cross-lagged associations between problem behaviors and teacher-student relationships in early adolescence
2017
This study investigated the cross-lagged associations between teacher-student relationships and problem behaviors in a sample of 440 Finnish students (half of them identified as being at risk of reading difficulties). The degree to which these associations were moderated by a child’s gender, academic performance, risk for reading difficulties, parental education, and having the same teacher over 2 years was examined. The teachers evaluated the students’ problem behaviors and reported closeness and conflict with a particular student. The results showed that the higher the students scored on externalizing problems in Grade 4, the more conflict teachers reported 2 years later. Moderator analy…
Think transformational leadership – Think female?
2015
This study examines whether the behaviors of transformational, transactional, and laissez-faire leadership are perceived as being more typical of female or male leaders. In a questionnaire study, 113 participants in Germany were asked to rate the probability of occurrence of a specific leadership behavior for male and female leaders, respectively. A diagnostic ratio for each leadership behavior allows the determination of the direction and degree of gender-specific evaluations. As predicted, transformational leadership is believed to be more typical of female leaders. Nevertheless, inspirational motivation and idealized influence attributed are rated as being gender neutral. For transactio…
The foundations of the new theories in health economics
1997
In health economics, theoretic approaches such as the theory of contracts, the economy of conventions, the theory of transaction costs and the evolutionary theory, have been applied recently. The present paper offers a classification of these different theories focusing on their epistemological foundations. The clarification of their assumptions about individual rationality (substantial or procedural rationality), about coordination modality (by inter-individual contracts or collective rules), about uncertainty (probabilistic risk or cognitive uncertainty), shows oppositions between these theories. Nevertheless, the application of these different theories in health economics shows that they…
Calibration of optimal execution of financial transactions in the presence of transient market impact
2012
Trading large volumes of a financial asset in order driven markets requires the use of algorithmic execution dividing the volume in many transactions in order to minimize costs due to market impact. A proper design of an optimal execution strategy strongly depends on a careful modeling of market impact, i.e. how the price reacts to trades. In this paper we consider a recently introduced market impact model (Bouchaud et al., 2004), which has the property of describing both the volume and the temporal dependence of price change due to trading. We show how this model can be used to describe price impact also in aggregated trade time or in real time. We then solve analytically and calibrate wit…
Portfolio optimisation with strictly positive transaction costs and impulse control
1998
One crucial assumption in modern portfolio theory of continuous-time models is the no transaction cost assumption. This assumption normally leads to trading strategies with infinite variation. However, following such a strategy in the presence of transaction costs will lead to immediate ruin. We present an impulse control approach where the investor can change his portfolio only finitely often in finite time intervals. Further, we consider transaction costs including a fixed and a proportional cost component. For the solution of the resulting control problems we present a formal optimal stopping approach and an approach using quasi-variational inequalities. As an application we derive a non…
European Option Pricing and Hedging with Both Fixed and Proportional Transaction Costs
2003
Abstract In this paper we provide a systematic treatment of the utility based option pricing and hedging approach in markets with both fixed and proportional transaction costs: we extend the framework developed by Davis et al. (SIAM J. Control Optim., 31 (1993) 470) and formulate the option pricing and hedging problem. We propose and implement a numerical procedure for computing option prices and corresponding optimal hedging strategies. We present a careful analysis of the optimal hedging strategy and elaborate on important differences between the exact hedging strategy and the asymptotic hedging strategy of Whalley and Wilmott (RISK 7 (1994) 82). We provide a simulation analysis in order …
American Option Pricing and Exercising with Transaction Costs
2005
In this paper we examine the problem of finding the reservation option prices and corresponding exercise policies of American options in a market with proportional transaction costs using the utility based approach proposed by Davis and Zariphopoulou (1995). We present a model where the option holder has a constant absolute risk aversion. We discuss the numerical algorithm and propose a new characterization of the option holder's value function. We suggest original discretization schemes for computing reservation prices and exercise policies of American options. The discretization schemes are implemented for the cases of American put and call options. We present the study of the optimal tra…
Indicators of improved learning contexts : a collaborative perspective on educational leadership
2015
The aim of this paper is to illustrate indicators for improved learning contexts based on the notion of collaborative leadership. Collaborative leadership refers to synergetic educational leadership practices through co-performance and a continuous and shared learning process. We argue that the indicators could serve as a bridge between education and the complex and increasing change within the social life and world of work. For finding the indicators, we combined two intertwining dimensions: ‘leadership in education’ and ‘education for leadership’. They were studied by a tested model describing collaborative leadership by a set of attributes. We then applied these attributes to a curriculu…
Symbolic leadership and leadership culture in one unified comprehensive school in Finland
2012
The research presented in this article is a description of the symbolic leadership and leadership culture in one unified comprehensive school in Finland. The study is a phenomenological qualitative case study based on triangulation. Leadership is studied through its functional, verbal and material dimensions. Leadership culture is regarded as one of the part cultures of the organisation culture. It is a product of the meaning and interpretation process which forms itself through the symbols of the principal's leadership. According to the present study, the leadership culture of the unified comprehensive school can be described as consisting of respect, communality, equality and humour.
Talking Blockchains: The Perspective of a Database Researcher
2021
There are few topics out there, that seem to create as much confusion and discussion as blockchains. This has a multitude of reasons: (1) A large number of drastically different concepts and systems are unified under the very broad term "blockchain". (2) The topic touches a variety of different fields, including databases, distributed processing, networks, cryptography, and even economics. (3) There exists a large number of different applications of the technology.The goal of this paper is to simplify and structure the discussion of blockchain technology. We first introduce a simple formalization of the basic components, that appear again and again in a variety of blockchain systems. Second…