The KLU faculty, post-docs, and PhD candidates regularly publish the results of their research in scientific journals. You will find a complete overview of all KLU publications below (e.g. articles in peer-reviewed journals, professional journals, books, working papers, and conference proceedings). Search for relevant terms and keywords, or filter the list by name, year of publication or type of publication. The references include DOIs and abstracts where available, and you can download them to your own reference database or platform. We regularly update the database with new publications.

Selected Publications

Copy reference link   DOI: doi:10.1007/s11116-012-9386-9

Abstract: This article analyzes the concept of logistics networks in the context of behavioral freight transport modeling. Starting from the basic definition of networks, the different perceptions of networks in transportation science and logistics are worked out. The micro‐macro gap, as a main challenge in freight transport modeling, is explained by the existence of logistics networks on a meso level. A taxonomy of modeling methods dealing with logistics networks is defined, based on two characteristics: the changeability of networks within models (fixed, partially variable and variable networks) and the form of cost functions mapped (economies of scale, constant average cost, and diseconomies of scale). For each category, different possible modeling methods and their application in existing freight transport models are discussed. A special focus is placed on methodologies and models that map variable networks.

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Copy reference link   DOI: 10.1016/j.obhdp.2011.10.006

Abstract: We examined how procedural fairness interacts with empowering leadership to promote employee OCB. We focused on two core empowering leadership types—encouraging self-development and encouraging independent action. An experiment revealed that leaders encouraging self-development made employees desire status information more (i.e., information regarding one’s value to the organization). Conversely, leaders encouraging independent action decreased employees’ desire for this type of information. Subsequently, a multisource field study (with a US and German sample) showed that encouraging self-development strengthened the relationship between procedural fairness and employee OCB, and this relationship was mediated by employees’ self-perceived status. Conversely, encouraging independent action weakened the procedural fairness-OCB relationship, as mediated by self-perceived status. This research integrates empowering leadership styles into relational fairness theories, highlighting that multiple leader behaviors should be examined in concert and that empowering leadership can have unintended consequences.

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Copy reference link   DOI: 10.1057/jibs.2012.15

Abstract: We argue that leader-directed voice (i.e., communicating critical suggestions for change to the leader) is a relational phenomenon, and that it is affected by an inherent feature of multinational teams: members’ (dis)similarities in nationality. We tested our hypotheses in a sample of middle managers who were working in multinational teams. The results of this study show that leaders of multinational teams are more likely to profit from the local know-how of employees from underrepresented nationalities when they are open to their ideas, and when they have the same nationality. The study also shows that the effects of being open to employees’ ideas and sharing the same nationality are mediated by affective commitment and psychological safety, respectively. We discuss how, even though the current relational demography perspective with its dichotomous understanding of (dis)similarity is not suited to capture the dynamics of cultural differences, it does set the stage for future studies to examine the cultural dynamics behind an individual's experience of being different from other team members in multinational teams. We also discuss the practical implications of these findings for multinational companies.

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Copy reference link   DOI: 10.4155/cmt.12.62

Abstract: This article examines the different approaches that companies can take to setting targets for the reduction of carbon emissions from their logistics operations. The research suggests that target-setting practices differ widely in this field. It is common for firms simply to apply corporate-level targets to logistics, despite the fact that carbon abatement potential and cost–effectiveness vary by function and activity. A small minority of firms have systematically analyzed the possible carbon savings from specific interventions and technologies. To improve their credibility and consistency, carbon reduction targets need to conform to certain principles. The article proposes a series of principles applicable to the decarbonization of logistics. It is based mainly on a literature review, semi-structured interviews with a sample of logistics managers and involvement in an industry-wide initiative to cut logistics-related carbon emissions.

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Copy reference link   DOI: http://dx.doi.org/10.1016/j.enpol.2012.08.049

Abstract: The reduction of greenhouse gases (GHG) is a highly prevalent public policy goal among European Union member countries. In the new White Paper on transport, the role of road freight transports in this is strongly emphasized. This far, however, the efficiency practices utilised in logistics firms are less studied. Drawing from policy goals and new survey data on 295 road transport firms our results show that hauliers are aware of the possible energy efficiency actions but lack the knowledge and resources to fully utilize them. Energy efficiency seems also to be unimportant for many shippers, so there are no incentives for hauliers to improve it. Examples from various countries show that clear energy efficiency improvements can be achieved with active cooperation between hauliers, shippers and policy makers. Such cooperation can be developed in Finland through the sectoral energy efficiency agreements. The novelty and the utility of these results allow scholars to answer important open questions in the national-level determinants of enhancing energy efficiency practices among road freight hauliers, and contribute to our understanding of how these can be fostered in public policies.

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Copy reference link   DOI: 10.1515/rmeef-2012-0004

Abstract: This paper estimates the Beveridge curve of Egypt for the period from 2004 to 2010, using quarterly data for both the private sector and the public sector. Our results confirm the negative relationship between unemployment and private job offers for the Egyptian labor market. The Beveridge curve has shifted inwards during the observation period, indicating an improved matching process between labor supply and private labor demand. However, the results for the public sector are poor, showing the Beveridge curve relation cannot be used to explain the relationship between government sector vacancy rates and the unemployment rate.

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Copy reference link   DOI: 10.3905/jai.2012.14.4.026

Abstract: The volatility of equity returns generally exhibits an asymmetric reaction to positive and negative shocks. Economic explanations for this phenomenon are leverage and a volatility feedback effect. This article studies the volatility of gold and demonstrates that there is an inverted asymmetric reaction to positive and negative shocks—positive shocks increase volatility more than negative shocks. The author argues that this effect is related to the safe-haven property of gold. Investors interpret positive gold price changes as a signal for future adverse conditions and uncertainty in other asset markets. This introduces uncertainty in the gold market and thus higher volatility. The empirical results hold for gold bullion and gold coins denominated in different currencies and for different return frequencies, sample periods, and distributional assumptions. Finally, the author shows that the inverted volatility effect of gold can lower the aggregate risk of a portfolio for specific correlation levels.

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Copy reference link   DOI: doi:10.1007/s10951-011-0249-6

Abstract: This paper presents and studies the Canadian Truck Driver Scheduling Problem (CAN-TDSP) which is the problem of determining whether a sequence of locations can be visited within given time windows in such a way that driving and working activities of truck drivers comply with Canadian Commercial Vehicle Drivers Hours of Service Regulations. Canadian regulations comprise the provisions found in U.S. hours of service regulations as well as additional constraints on the maximum amount of driving and the minimum amount of off-duty time on each day. We present two heuristics and an exact approach for solving the CAN-TDSP. Computational experiments demonstrate the effectiveness of our approaches and indicate that Canadian regulations are significantly more permissive than U.S. hours of service regulations.

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Copy reference link   DOI: 10.1287/trsc.1110.0382

Abstract: The U.S. truck driver scheduling problem (US-TDSP) is the problem of visiting a sequence of λ locations within given time windows in such a way that driving and working activities of truck drivers comply with U.S. hours-of-service regulations. In the case of single time windows it is known that the US-TDSP can be solved in O(λ3) time. In this paper, we present a scheduling method for the US-TDSP that solves the single time window problem in O(λ2) time. We show that in the case of multiple time windows the same complexity can be achieved if the gap between subsequent time windows is at least 10 hours. This situation occurs, for example, if, because of opening hours of docks, handling operations can only be performed between 8.00 a.m. and 10.00 p.m. Furthermore, we empirically show that for a wide range of other problem instances the computational effort is not much higher if multiple time windows are considered.

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Copy reference link   DOI: doi:10.1007/s10696-011-9086-3

Abstract: This paper studies the problem of scheduling working hours of team drivers in European road freight transport where a sequence of lambda locations must be visited within given time windows. Since April 2007 working hours of truck drivers in the European Union must comply with regulation (EC) No 561/2006. These regulations impose standard limits on the daily driving times of truck drivers and extended daily limits that may only be used twice a week for each driver. We present a depth-first-breadth-second search method which can find a feasible schedule complying with standard daily driving time limits in O(lambda^2) time, if such a schedule exists. Furthermore, we show that this method can also be used to find schedules complying with regulation (EC) No 561/2006 if daily driving times may exceed the standard limit.

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Copy reference link   DOI: 10.1007/s00187-012-0157-8

Abstract: Cost reduction is usually confronted with conflicts and resistance. Besides planning and controlling measures the management accounting literature discusses behavioral and organizational factors (e.g., top management commitment, participation, cost culture) in order to overcome this resistance. Thus, from a theoretical perspective different concepts exist for implementing an effective long-term cost reduction. However, only little empirical research can be found that investigates the relative importance of “soft” behavioral and implementation factors compared to general planning and control measures. This study examines the role of behavioral and organizational (“soft”) factors in comparison to planning and control (“hard”) factors in cost reduction projects. Target costing or activity-based costing projects represent examples for strategic cost reduction projects which are considered in this study. The sample comprises 131 chief management accountants of medium-size and large German companies which were involved in such strategic cost reduction projects. Structural equation modeling is used for deriving the results. The results show that cost culture, top management commitment, and participation are of particular importance for the success of cost reductions. Their influence drives significantly planning and controlling measures which in turn determine the effectiveness of cost reduction measures.

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Copy reference link   DOI: 10.1016/j.cor.2011.05.021

Abstract: In September 2008 new regulations for managing heavy vehicle driver fatigue entered into force in Australia. According to the new regulations there is a chain of responsibility ranging from drivers to dispatchers and shippers and thus, carriers must explicitly consider driving and working hour regulations when generating truck driver schedules. This paper presents and studies the Australian Truck Driver Scheduling Problem (AUS-TDSP) which is the problem of determining whether a sequence of locations can be visited within given time windows in such a way that driving and working activities of truck drivers comply with Australian Heavy Vehicle Driver Fatigue Law.

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Copy reference link   DOI: 10.1016/j.cor.2011.12.016

Abstract: In Canada transport companies must ensure that truck drivers can comply with Canadian Commercial Vehicle Drivers Hours of Service Regulations. Canadian regulations comprise the provisions found in US hours of service regulations as well as additional constraints on the maximum amount of driving and the minimum amount of off-duty time on each day. This paper presents a mixed integer programming formulation and an iterative dynamic programming approach for minimising the duration of truck driver schedules complying with Canadian hours of service regulations. Computational experiments show that schedule durations can be significantly reduced compared with a previously presented approach which only focuses on feasibility.

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Copy reference link   DOI: http://dx.doi.org/10.1016/j.jbankfin.2011.05.019

Abstract: This paper studies the spread of the Global Financial Crisis of 2007–2009 from the financial sector to the real economy by examining ten sectors in 25 major developed and emerging stock markets. The analysis tests different channels of financial contagion across countries and sectors and finds that the crisis led to an increased co-movement of returns among financial sector stocks across countries and between financial sector stocks and real economy stocks. The results demonstrate that no country and sector was immune to the adverse effects of the crisis limiting the effectiveness of portfolio diversification. However, there is clear evidence that some sectors in particular Healthcare, Telecommunications and Technology were less severely affected by the crisis.

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Copy reference link   DOI: http://dx.doi.org/10.1016/j.ejor.2011.11.030

Abstract: Nowadays, especially in developed countries, the traditional collection of end-of-use products by scavengers has been displaced by formal waste recovery systems. However, scavenging still exists, especially in places with collection capacity shortages and/or low living standards. Besides its obvious social implications, the financial and environmental aspects of scavenging are certainly not trivial. Informal recycling of waste electrical and electronic equipment (WEEE) by scavengers not only constrains profits of the formal system. In their effort to recover the value of end-of-use products, scavengers also pollute the environment if toxic substances leak when WEEE is not properly disposed of. We investigate the impact of scavenging on the operations of the formal recovery system of WEEE, under three regulatory measures, using system dynamics methodology. By using data from a real world closed-loop supply chain that operates in Greece extended numerical experimentation revealed that a legislation incorporating scavengers into the formal waste recovery system (instead of either ignoring or prohibiting their participation) is beneficial for economical, environmental and social sustainability.

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Copy reference link   DOI: 10.1016/j.ejor.2011.06.033

Abstract: We develop an approximate dynamic programming approach to network revenue management models with customer choice that approximates the value function of the Markov decision process with a non-linear function which is separable across resource inventory levels. This approximation can exhibit significantly improved accuracy compared to currently available methods. It further allows for arbitrary aggregation of inventory units and thereby reduction of computational workload, yields upper bounds on the optimal expected revenue that are provably at least as tight as those obtained from previous approaches. Computational experiments for the multinomial logit choice model with distinct consideration sets show that policies derived from our approach can outperform some recently proposed alternatives, and we demonstrate how aggregation can be used to balance solution quality and runtime.

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Copy reference link   DOI: 10.1111/j.1937-5956.2011.01251.x

Abstract: Supply chain risk management (SCRM) is a nascent area emerging from a growing appreciation for supply chain risk by practitioners and by researchers. However, there is diverse perception of research in supply chain risk because these researchers have approached this area from different domains. This paper presents our study of this diversity from the perspectives of operations and supply chain management scholars: First, we reviewed the researchers' output, i.e., the recent research literature. Next, we surveyed two focus groups (members of Supply Chain Thought Leaders and International SCRM groups) with open-ended questions. Finally, we surveyed operations and supply chain management researchers during the 2009 INFORMS meeting in San Diego. Our findings characterize the diversity in terms of three “gaps”: a definition gap in how researchers define SCRM, a process gap in terms of inadequate coverage of response to risk incidents, and a methodology gap in terms of inadequate use of empirical methods. We also list ways to close these gaps as suggested by the researchers.

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Copy reference link   DOI: doi:10.1007/s13676-012-0014-9

Abstract: Truck driver scheduling problems are important subproblems of real-life vehicle routing and scheduling problems because rest periods required by government regulations have a significant impact on travel and arrival times and vehicle routes generated without considering these regulations are often practically infeasible. This paper presents a mixed integer programming formulation and a dynamic programming approach for solving a variant of the truck driver scheduling problem in which truck drivers may only rest at customer locations and at suitable parking lots. The objective of the problem is to find a truck driver schedule with minimal duration. The model presented in this paper is very flexible and can be configured to consider different sets of rules imposed by government regulations and union contracts. The effectiveness of the dynamic programming approach is demonstrated for working hour regulations in the United States and in the European Union.

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Copy reference link   DOI: 10.1007/s10951-012-0282-0

Abstract: Transport companies seek to maximise vehicle utilisation and minimise labour costs. Both goals can be achieved if the time required to fulfil a sequence of transportation tasks is minimised. However, if schedule durations are too short drivers may not have enough time for recuperation and road safety is impaired. In Australia transport companies must ensure that truck drivers can comply with Australian Heavy Vehicle Driver Fatigue Law and schedules must give enough time for drivers to take the amount of rest required by the regulation. This paper shows how transport companies can minimise the duration of truck driver schedules complying with Australian Heavy Vehicle Driver Fatigue Law. A mixed integer programming formulation is presented and valid inequalities are given. Computational experiments show that these inequalities provide significant reduction in computational effort when using one of the most advanced commercial mixed integer programming solver.

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Copy reference link   DOI: 10.1016/j.ijresmar.2012.03.001

Abstract: The methodological discussion on the calibration of aggregate marketing response models has shifted away from how to obtain usable input for optimization toward how to avoid biases in statistical estimation. The purpose of this article is to remind researchers that such calibration is performed either to support managers in their marketing-mix decisions or to create general knowledge that leads to a better understanding of marketing relationships and thus indirectly supports decisions. Both goals require response models that are optimizable. The models must also be implementable if actual decision support is the objective. Herein, I identify several aspects for which these requirements are not always fulfilled: First, the appropriateness of the chosen functional form of the marketing response models is rarely discussed, although different forms imply quite different optimal solutions. Second, endogeneity is taken into account by structural equations, even though we lack sufficient information on how managers reach their decisions. Third, estimation methods for response models are often evaluated based on goodness-of-fit, while an assessment of their usefulness for subsequent optimization is neglected. Therefore, I provide recommendations for improving the current practice by better specifying the response function and undertaking more simulation-based evaluations of the best estimation method for use in subsequent optimization. With respect to implementation, usability can be facilitated using spreadsheets and heuristics. Moreover, gaining generalizable and replicable knowledge requires better documentation of results, which can be achieved through providing elasticities and as many details as are necessary to replicate a study, thereby enabling faster learning.

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Copy reference link   DOI: 10.2139/ssrn.2142283

Abstract: Gold has been a store of value for centuries and a safe haven for investors in the pastdecades. However, the increased investment in gold for speculative or hedging purposes has changed the safe haven property. We demonstrate theoretically and empirically that investor behaviour has the potential to destroy the safe haven property of gold. The results suggest that an asset cannot be both an investment asset and an effective safe haven asset. This finding has important implications for financial stability since assets are more likely to exhibit excess comovement and volatility in the absence of a safe haven.

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Copy reference link   DOI: 10.1525/cmr.2012.54.3.98

Abstract: Outsourcing initiatives are key to firm efforts to focus on core competencies, alter engrained practices and attain significant cost reductions in non-core processes. Extensive thought goes into the selection of outsourcing service providers, with the aim of enlisting vendors that have the competence and reputation to lower cost and enhance service levels. However, in addition to traditional fee-for-service outsourcing, another option is to develop a new enterprise that is wholly or partially owned by the outsourcing entity to take on the activities that are externalized—a so-called “enterprise partnership.” This article examines one of the first examples of such a partnership: BAE Systems' efforts to outsource its HR services in collaboration with Xchanging. It tracks the evolution of the resulting enterprise partnership from the perspective of both the new vendor and the outsourcing firm. The article also discusses the need for explicit contractual recognition of key phases of the outsourcing life cycle as a means to reduce inevitable in-process conflict. Understanding the divergence of interests that naturally emerge is critical to realizing the long-term promise that enterprise partnerships offer.

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Copy reference link   DOI: 10.1016/j.socscimed.2011.02.011

Abstract: In an effort to improve operational efficiency, healthcare services around the world have adopted process improvement methodologies from the manufacturing sector, such as Lean Production. In this paper we report on four multi-level case studies of the implementation of Lean in the English NHS. Our results show that this generally involves the application of specific Lean ‘tools’, such as ‘kaizen blitz’ and ‘rapid improvement events’, which tend to produce small-scale and localised productivity gains. Although this suggests that Lean might not currently deliver the efficiency improvements desired in policy, the evolution of Lean in the manufacturing sector also reveals this initial focus on the ‘tool level’. In moving to a more system-wide approach, however, we identify significant contextual differences between healthcare and manufacturing that result in two critical breaches of the assumptions behind Lean. First, the customer and commissioner in the private sector are the one and the same, which is essential in determining ‘customer value’ that drives process improvement activities. Second, healthcare is predominantly designed to be capacity-led, and hence there is limited ability to influence demand or make full use of freed-up resources. What is different about this research is that these breaches can be regarded as not being primarily ‘professional’ in origin but actually more ‘organisational’ and ‘managerial’ and, if not addressed could severely constrain Lean’s impact on healthcare productivity at the systems level.

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Abstract: Marketing budget decisions are critical and should be fact based rather than intuitive. Profit can be improved by better allocating a fixed budget across products or regions. The Excel-based decision support model presented in this article makes it possible to determine near-optimal marketing budgets and represents an innovative and feasible solution to the dynamic marketing allocation budget problem for multi-product, multi-country firms. The model accounts for marketing dynamics and a product's growth potential as well as for trade-offs with respect to marketing effectiveness and profit contribution. It was successfully implemented at Bayer, one of the world's largest firms in the pharmaceuticals and chemicals business. The profit improvement potential in this company was more than 50 % and worth nearly EUR 500 million in incremental discounted cash flows.

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