Airline network structure under demand uncertainty

In this paper, we provide another reason that may explain the adoption of the hub-and-spoke network structure in the airline industry. We show that when an airline has to decide on its capacity before the demand conditions are perfectly known, a hub-and-spoke (h&s) network structure by pooling passengers from several markets into the same plane helps the firm to lower its cost of excess capacity in the case of low demand and to improve its capacity allocation in the case of high demand.     

Allocating collaborative costs in multimodal barge networks for freight bundling

In order to improve the competitive position and efficiency level of multimodal transport, consolidation of freight flows is often suggested. Bundling networks require cooperation between multiple partners in the multimodal transport chain. In this context, the question rises how benefits may be allocated fairly among the spatially distributed participants in the cooperation. A great deal of scientific literature reports on the behavior of allocation methods in collaborations between shippers or carriers making use of unimodal road transport. However, research on cost or savings allocation methods in multimodal transport is scarce. The main contribution of this paper is thus to provide a first insight in the complexity of sharing cost savings fairly among shippers who bundle freight flows in order to reach economies of scale in multimodal barge transport. By applying four different allocation methods to two realistic case studies, a comparison is made between simple and straightforward allocation mechanisms and more advanced techniques based on cooperative game theory. Special attention is paid to the savings division among coalition partners and collaborative stability. Results demonstrate the influence of cooperation characteristics on allocation outcomes and underline the value of carefully selecting appropriate allocation mechanisms when long-term stability of the multimodal barge collaboration is aspired.     

我国交通运输业的外部成本研究

在论述运输业外部成本的定义和种类的基础上,分析运输业外部成本对资源配置的影响。运用运输业外部成本的定量评估方法对我国各种运输方式的单位外部成本和总外部成本进行了计算评估,并针对我国运输业的发展现状提出外部成本内部化的建议。     

The airfare pricing and seat allocation problem in full-service carriers and subsidiary low-cost carriers

This study investigates the competitive market situation in the air transport industry considering full-service carriers (FSC), subsidiary low-cost carriers (LCC) and rival LCCs on the flight-leg level while subsidiary LCCs are established by FSCs against rival LCCs to keep the market share and to make more profit. It is assumed that the demand of economy class for each airline follows a known distribution, and the mean value of that distribution is a function of its airfare and the airfare differences with other airlines. In addition, no-shows and cancellations are introduced to reflect a real situation. Based on this situation, a mathematical model is developed to derive efficient airfare pricing and seat allocation for each airline for maximizing the profit sum of both FSCs and subsidiary LCCs using a repeated game. A repeated game model integrated with a Tabu search algorithm and an EMSR based heuristic is suggested to deal with the proposed repeated game. A numerical example is provided to validate the model and solution procedure with hypothetical system parameter values under two kinds of market situations that show before and after the emergence of subsidiary LCCs.     

基于技术站改编作业的集装箱空箱调运优化模型

以降低铁路集装箱空箱调运成本为出发点,建立空箱调运整数规划模型。该模型目标是空箱调运过程中产生的运输走行费用、技术站改编费用和积压库存费用或延误损失费用之和最小,在满足空箱需求与供应能力的基础上,考虑技术站改编时间和运输走行时间对空箱需求站时间窗的影响,以及车站作业能力的限制。运用LINGO软件对模型求解,并进行了算例分析。     

Incorporating inventory control decisions into a strategic distribution network design model with stochastic demand

In this paper, we propose a simultaneous approach to incorporate inventory control decisions––such as economic order quantity and safety stock decisions––into typical facility location models, which are used to solve the distribution network design problem. A simultaneous model is developed considering a stochastic demand, modeling also the risk pooling phenomenon. We present a non-linear-mixed-integer model and a heuristic solution approach, based on Lagrangian relaxation and the sub-gradient method. In a numerical application, we found that the potential cost reduction, compared to the traditional approach, increases when the holding costs and/or the variability of demand are higher.     

What comes next after recession? – Airline industry scenarios and potential end games

While airline managers learned lessons from the 2001/2003 “double dip” economic crisis, the post 2008 downturn has been more extreme. Airlines reacted quickly in 2008 and adjusted capacities and cost levels but recovery in profits has been slow for many airlines. The dynamics of the downturn has enlarged the gap between successful and less successful business models, and fostered shakeouts of the latter. Furthermore, the occurrence of new business models has accelerated. In 2001, it was the European continental low cost model; this time, we may see new attempts to change the rules of the game in international long-haul traffic. Long-term non-cyclical trends such as deregulation or consolidation will also shape potential end game scenarios, We briefly examine the differences between the last (2001/03) and the recent (2008/09) aviation crises, and evaluate the impact on different types of carriers.     

Analysis on bargaining about global climate change mitigation in international aviation sector

Understanding the basic interaction mechanism among nations surrounding the CO₂ emissions is critically important for the policy formulation analysis in aviation sector at present, especially for market-based measures such as emission allowance trading. We performed simulation analysis of the effects on pricing of emission allowances by including major players such as China and India into the hypothetical global CO₂ emission trading scheme according to non-cooperative game framework. In the presence of a negative public good, i.e., CO₂, we extended the Lindahl–Bowen–Samuelson condition to include a class of uncertainty typical in climate change policy into utility. By using the result, we explained, with some numerical examples, the welfare effects caused by the changes of factors, such as level of uncertainty, degree of risk averse, asymmetric utility structure, initial allocation among players, based on our model surrounding the bargaining of CO₂ emissions allocation games.     

An airline's management strategies in a competitive air transport market

Over the last decade, the demand for domestic and international flights in Korea has increased substantially. To meet the strong flight demands, several low cost carriers have begun to offer flight services. In addition, full service carriers have been motivated to establish their own subsidiary low cost carriers to maintain their market share against rival low cost carriers. This paper studies the management strategies of three kinds of airlines - full service carrier, its subsidiary low cost carrier and rival low cost carrier - based on game theory in the competitive air transport market. Each airline is assumed to act as a player and chooses strategies regarding airfare, flight frequency, and the number of operating aircrafts for specific routes while maximizing its own profits. Demand leakages between the airlines are considered in the flight demand function according to the selected strategies of all airlines. Through various game situations reflecting realistic features, this study provides managerial insights that can be applied in the competitive air transport market.     

Models for relief routing: Equity, efficiency and efficacy

In humanitarian relief operations, vehicle routing and supply allocation decisions are critically important. Similar routing and allocation decisions are studied for commercial settings where efficiency, in terms of minimizing cost, is the primary objective. Humanitarian relief is complicated by the presence of multiple objectives beyond minimizing cost. Routing and allocation decisions should result in quick and sufficient distribution of relief supplies, with a focus on equitable service to all aid recipients. However, quantifying such goals can be challenging. In this paper, we define and formulate performance metrics in relief distribution. We focus on efficacy (i.e., the extent to which the goals of quick and sufficient distribution are met) and equity (i.e., the extent to which all recipients receive comparable service). We explore how efficiency, efficacy, and equity influence the structure of vehicle routes and the distribution of resources. We identify trends and routing principles for humanitarian relief based on the analytical properties of the resulting problems and a series of computational tests.     

Shipowner preferences and user charges: allocating port infrastructure costs

The main aim of this paper is to present a pricing mechanism appropriate for allocating common maritime infrastructure cost which would allow not only a fair and efficient allocation, but also, a solution which would take into account demand characteristics assuring a realistic interpretation of market’s behaviour. The proposed solution concept is that of the “ratio equilibrium”. Its main qualities consist in guaranteeing a balanced budget, and being – from a strategic point of view – a stable solution. In other words, no port user will be discouraged from using the infrastructure by the assignment of a cost-share that is too high. This latter feature adds a competitive element into the calculations and can be considered as an innovative feature of this analysis. A numeric example is presented.     

外部性理论在运输业中的应用及发展

对外部性理论的形成及基本理论观点、分析方法、应用价值进行评述,揭示出运输外部性在外部性理论研究中的重要地位。阐述了外部性理论在运输经济研究和运输产业发展中的应用现状及存在的问题,结合运输业的发展趋势,提出外部性理论在未来运输产业应用研究中的发展方向。结论认为,运输外部性边界界定、最优解决方案、利害相关者博弈、外部成本计量的精确性和年鉴化等领域的研究,应成为未来应用性研究的努力方向。     

Modeling port competition from a transport chain perspective

This paper considers the competition between two ports involving both hinterland shipments and transhipments. Taking a transport chain perspective including deep-sea, port, feeder and inland transportation, we present a static cost model to examine ports’ relative competitiveness and justify the development of game models. A non-cooperative game model is then formulated for a two-ports-one-ocean carrier system. The optimal ports’ pricing and the carrier’s port-of-call decisions are derived. A centralized supply chain model is then discussed. The game model is further extended to uncertain demand situations. A case study of Southampton and Liverpool ports is provided to illustrate the results.     

Is economics good for aviation policy? Some problems in bridging the gap between theory and policy

This paper argues that airport economics is based on the concept of economics as the positive value free science of efficient allocation of scarce resources with given wants, ignoring the approach of economics as a moral science. It assesses critically the results on major policy issues. Although there is strong empirical evidence of natural monopoly of airports, no consensus has emerged. The effects of privatisation have been assessed in terms of cost efficiency, but not in terms of economic welfare and distribution. While airport economics has made theoretical progress, the policy recommendations on single versus dual till are less relevant than those from the older models. Airport expansion is assessed in many cases by economic impact studies instead of cost benefit analysis. Economists applying impact analysis, have contributed to an irrational policy discussion. The role for morals in the management of airports has been neglected, although there is evidence that incentives might backfire. The paper argues that airport economics based on economics as a moral science could improve airport economics, and make its policy recommendations more relevant.     

Delivery leadtime and channel structure decisions for make-to-order duopoly under different game scenarios

We develop game-theoretic models to explore the quoted delivery leadtime, price, and channel structure decisions for a make-to-order duopoly system under three game scenarios. Under the integrated-manufacturer first scenario, we find that (i) decentralization of the supply chain increases quoted leadtime; and (ii) both manufacturers may choose different channel structures under symmetric duopoly. By comparing with the symmetric scenario and the retailer first scenario, we find that a manufacturer facing a decentralized rival adopts decentralization when leadtime sensitivity, leadtime cost, and price elasticity are very small; the effect of decentralization on quoted leadtime largely depends on game scenario.     

A model for taxi pooling with stochastic vehicle travel times

Taxi pooling means the sharing of a taxi by more than one passenger with at least a semi-common route. Currently, a trial-and-error process is adopted, taking into account expected travel times, for taxi pooling, a method which is neither effective nor efficient. This is because stochastic disturbances arising from variations in the taxi travel times that occur in actual traveling are neglected. In the worst case scenario, where vehicle travel times fluctuate wildly during operations, the planned schedule can be disturbed enough to lose its optimality. Therefore, in this study, a network flow technique is used to construct a stochastic taxi pooling model incorporating stochastic vehicle travel times. A solution algorithm is also proposed to efficiently solve the problem. The performance of the proposed models and the use of the solution method in practice are evaluated by executing numerical tests using real data with suitable assumptions. The test results show that the stochastic model and the solution method could be useful references for practice.     

Cost-effective pallet management strategies

The existing industry strategies for managing pallets, (single-use expendable pallets, buy/sell programs, and leased pallet pooling programs), are analyzed and compared using push and pull inventory control policies. A two-stage integrated framework is developed that combines cost relationship models with data gathered in industry with multi-echelon inventory performance measures. For the base case, the single-use expendable pallet approach presents the least cost of all strategies, but the leased pallet pooling programs outperform the buy/sell programs in terms of total cost. The intervals where each strategy is most attractive are shown with respect to pallet cost, salvage cost, dwell fees, effective issue fees, retention rates, and transportation costs.     

Phased implementation of transport pricing for Greater Oslo

We apply a modelling framework, RETRO, based on the land use and transport models for determination of implementation paths for marginal social cost pricing of passenger transport in Greater Oslo. Marginal social cost pricing strategies are assessed through welfare maximisation with respect to the transport instruments that are available. We have constructed implementation paths unconstrained and constrained with regard to acceptable levels of transport instruments, financial situation and equity. The implementation paths are evaluated relative to a base-case situation with continuation of today's pricing policy. The evaluation includes a discussion of the effects on land use and transport indicators.     

Can low cost carriers deter or accommodate entry?

This paper analyses entry deterrence and accommodation by low cost carriers (LCCs) with two games. In the first game two LCCs compete in a horizontal differentiation setting. Results show that the entrant may drive away the incumbent from its original location under certain conditions. In the second game the incumbent is a LCC and the entrant a full service carrier, with vertical differentiation. The incumbent tries to deter or accommodate entry by product proliferation. We find out that the incumbent will only deter entry if it can surpass the entrant’s quality, and that product proliferation is not an accommodating strategy.     

Cost adjustment for single item pooling models using a dynamic failure rate: A calculation for the aircraft industry

This paper presents an analytical model for cost estimation in a single-item, multi-hub (S-1,S) inventory policy-pooling model for high-value spare parts in the aviation industry. The model extends existing, static pooling models by implementing a dynamic failure rate, using a maintenance free operating period (MFOP) as a measurement technique to increase availability of aircraft components. The gained results through a dynamic failure rate show significant effects for a reduction of total costs of ownership and achieving a better operational stock planning, which is demonstrated in a numerical application.