A note on the competitive advantage of large hub-and-spoke networks

This note explores the extent to which airlines operating large hub-and-spoke networks secure a competitive advantage. More specifically, this paper explores the intricate relationship which arises among productive efficiencies and profitability when the size of the hub-and-spoke network expands. To this end, Brueckner and Spiller (1991, International Journal of Industrial Organization 9, 323–342) airline economics model is generalized by allowing the size of the hub-and-spoke network to vary. The central result shows that, although the model exhibits decreasing returns to firm/network size (RTNS), nonetheless there is a competitive advantage to increasing the size of a network.     

Study of the topology and robustness of airline route networks from the complex network approach: a survey and research agenda

Communication via air routes is an important issue in a world organized around a web city network. In this context, the robustness of network infrastructures, e.g. air transport networks, are a central issue in transport geography. Disruption of communication links by intentional causes (e.g., terrorist attack on an airport) or unintentional (e.g., weather inclemency) could be crucial for countries, regions and even the airlines affected themselves. Policymakers and the management of airlines and alliances should be able to reduce the effects of such interruptions in order to ensure good communication through air transport (i.e., maximize the robustness of their network at a reasonable cost). The literature review of the study of air transport route networks through an analysis of complex networks has highlighted a lack of contributions to the study of the topology and the robustness of such networks which contrasts, with advances undertaken for other transport networks or communication systems. This survey suggests areas in which research should be undertaken, based on the existing literature in other areas and from three different perspectives: global route networks, airline alliances, airlines and airports so as to help towards a better understanding of air traffic and, therefore, to be able to assess the potential damage of any airport being inoperative for a continent, country or airline.     

Post pandemic aviation market recovery: Experience and lessons from China

China was the first aviation market in the world hit hard by COVID-19 and has been recovering gradually as the pandemic became largely under control within mainland China. This study reviews the recovery pattern influenced by the Chinese government's aviation policy choices, in the hope that our discussions and findings will help improve aviation policy responses elsewhere. While the domestic market in mainland China has enjoyed a quick recovery to about 80% of the pre-crisis level by July 2020, the recovery of international services has been much slower, due to the bilateral route and flight frequency/capacity control and strict requirements for health check and quarantine. China's domestic aviation market was recovered by about 80% in two months after the pandemic became under good control. Most other countries with a “curve flattening” strategy, instead of full pandemic control, may not expect the fast recovery path China has achieved. A British “travel corridor” approach may be more practical for Western countries to follow, albeit more likely to be subject to serious setbacks and disruptions. The aviation fee reductions and cost support China and many other countries have been using are helpful by reducing airlines' marginal costs, but not sufficient for carriers to return to profitability or sustainable operations. Capital injection and/or credit guarantee may be needed for many airlines to survive. With various, often uncoordinated, regulations imposed in international markets, airlines based in open economies that have small domestic markets will face particularly serious challenges during the recovery process.     

Temporal configurations of European airline networks

The deregulation of the US domestic airline industry resulted in the reconfiguration of airline networks into hub-and-spoke systems. In contrast to the US airlines, airlines in Europe already operated spatially concentrated networks long before deregulation. This concentration at the national home-base was the outcome of bilateral traffic rights designated to the national carrier. With a few exemptions, however, most of these star-shaped networks were not coordinated in time. Transfer opportunities at most national airports only existed by accident. Only airports that were operated as gateways to Europe provided planned connectivity between intercontinental flights and European feeder services. The deregulation of the EU market stimulated a second phase of airline network restructuring. European airlines concentrated their networks by adopting or intensifying wave-system structures (‘banks’ to use the US term) in their flight schedules. This paper investigates these post-deregulation temporal concentrations in European aviation networks. The development and configuration of wave-system structures at European airline hubs is analyzed as well as the resulting transfer opportunities during the 1990s. It is found that a temporal concentration trend exists among European airlines with deregulation resulting in the adoption or intensification of wave-system structures by airlines. These wave-system structures, as well as overall traffic growth, have significantly stimulated the number of indirect hub connections. Airline hubs with wave-system structures generally perform better because of the increased indirect connectivity given the number of direct connections.     

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.     

The effect of code-sharing alliances on airline profitability

Code sharing and global alliances both have been increasingly adopted by airlines worldwide in recent years. A growing number of airlines, therefore, are embedded in networks of multilateral “coopetitive” (i.e., cooperative, but competitive) relationships that influence their product offering, pricing strategies, operating efficiency, market power, and their overall successes. There has been considerable research analyzing the benefits for airlines from joining global alliances, including bilateral code-sharing partnerships. However, the joint effect of code-sharing and global alliances on airline performance has not been fully investigated. In this paper, we study how the use of code-sharing strategies and their structural embeddedness into global alliances may impact airline performance. Using a unique dataset compiled from Flight Global and Airline Business's Annual Airline Alliance Report, the paper empirically investigates the joint benefits of code-sharing partnerships and global alliances on airline profitability. The results based on a group of 81 airlines during the 2007–2012 period show that the profit margin of an airline is positively associated with the number of code-sharing partners it has. Furthermore, the profit margin gains from code-sharing are greater when an airline has a higher proportion of its code-sharing partners in the same global alliance; i.e., allied code-sharing partners. Finally, we find no significant evidence that the percent of comprehensive code sharing partnerships to total partnerships has an impact on profit margin.     

Different models in different spaces or liberalized optimizations? Competitive strategies among low-cost carriers

This paper asks whether the economic success of low cost carriers (LCCs) has been achieved through optimizations of network structures to liberalized market conditions. By examining the network structures of six successful LCCs, the paper moves away from the idea of a “low cost carrier model” and instead highlights the range of spatial strategies employed by budget airlines in liberalized marketplaces. Findings show that significantly different spatial models are employed by the six carriers examined in this study. Unlike previous studies on the networks structures of LCCs, this paper moves beyond any one specific region and looks at the networks of budget airlines in Asia, Europe, and North America. Fundamental differences in the network structures of LCCs on these three continents indicate that liberalization has allowed for the utilization of a variety of spatial operating models rather than a singular optimal model.     

Airline mergers and their effect on network structure

The Airline Deregulation Act of 1978 introduced high-level competition into the US domestic industry. The resulting network changes have created a deluge of research, largely focused on the hub-and-spoke structure. Over 15 years have passed since deregulation, and the industry still appears somewhat unsettled. Recent concerns of domestic carriers include downsizing of some hubs, and discussions of further consolidation of operations. Mergers may be the answer for airlines with shrinking markets within the US transportation system. This study examines the effect on network structure created by the merger of two carriers from the perspective of hub structures, accessibility and geographic coverage.     

How did COVID-19 impact air transportation? A first peek through the lens of complex networks

The current outbreak of COVID-19 is an unprecedented event in air transportation. This is probably the first time that global aviation contributed to the planet-wide spread of a pandemic, with casualties in over two hundred countries. As of August 23rd, 2020, the number of infected cases has topped 23 million, reportedly relating to more than 800,000 deaths worldwide. However, there is also a second side of the pandemic: it has led to an unmatched singularity in the global air transportation system. In what could be considered a highly uncoordinated, almost chaotic manner, countries have closed their borders, and people are reluctant/unable to travel due to country-specific lock-down measures. Accordingly, aviation is one of the industries that has been suffering most due to the consequences of the pandemic outbreak, despite probably being one of its largest initial drivers. In this study, we investigate the impact of COVID-19 on global air transportation at different scales, ranging from worldwide airport networks where airports are nodes and links between airports exist when direct flights exist, to international country networks where countries are contracted as nodes, and to domestic airport networks for representative countries/regions. We focus on the spatial-temporal evolutionary dynamics of COVID-19 in air transportation networks. Our study provides a comprehensive empirical analysis on the impact of the COVID-19 pandemic on aviation from a complex system perspective using network science tools.     

Chapter 11 and the level playing field: Should chapter 11 be considered as a subsidy?

This paper assesses whether Chapter 11 is a form of subsidy for US airlines. US airlines have used Chapter 11 to restructure their operations. This has been criticized as a subsidy by major non US airlines and governments for a long time and recently, in the “level playing field” debate. Applying legal and economic perspectives of subsidy, we examine the different opportunities of Chapter 11 to reduce airlines’ costs. It is argued that most of the forms available, such as the modification of collective bargaining, do not constitute a subsidy. Only the termination of pension plans might involve a subsidy, but only using a legal definition of doubtful relevance since there is normally no use of public funds.     

Debunking some common myths about airport hubs

Much of the passenger air transportation market is served through hub-and-spoke operations with traffic being funneled through a number of major airports. This system has come under attack as protective of the airlines that center their operations on large hubs and is often as result, seen as not serving the public interest. This paper looks at some of the arguments that have been laid against the hub-and-spoke system. It does not offer a balanced perspective in that there are many problems with the system that are not touched upon here, but rather it seeks to question some of the economic logic that has been used to attack the hub-and-spoke structure. While the issues extend to many air transportation markets, the focus here is primarily on the US domestic situation.PrologueThe impacts of the events of September 11, combined with the move into economic recession in the US that was already underway at that time, have led to serious financial difficulties for many of the World's airlines. Some, such as Midway in the US, immediately sought bankruptcy protection whilst others, such as Sabena and Swissair in Europe, took a little longer to fade away. Most of those that remain, despite combinations of financial assistance, have been struggling in the current economic climate.The subject addressed here is not directly concerned with this issue, although there are important overlapping longer-term linkages. Rather it looks at the structure of the airline networks that dominate the provision of air services. These structures still remain, although there are inevitable changes occurring. This paper was initially drafted prior to the recent changes that have taken place in air transportation markets. It retains much of the original material that was presented at the Amsterdam meeting, with some minor up-dating. The theme may seem less important now than at the time of the meeting, but this, I would argue, is perhaps a premature view. The combination of derived demand, relatively easy market entry, lumpiness in investments, etc., have resulted over time in dramatic changes in the fortunes of the sector and individual actors in it. There are, though, a number of recurring themes that pose interesting questions for the applied economist and one of these is the nature of efficient networks.     

Restructuring Argentina's airline networks: Successes and challenges

Argentina's aviation networks underwent significant restructuring after the 2015 election of President Mauricio Macri. Historically constrained by poor aviation infrastructure, economic uncertainty, currency devaluations, labor unrest, comparatively weak passenger demand, and operational barriers to low-cost carriers (LCCs), Argentina's airline networks have experienced deep restructuring in both providers and network interactions. With less than 0.3 trips per capita in Argentina, compared to 3.0 in the mature U.S. aviation market, analysts argue that there is significant potential for moving bus and automobile travelers to airlines, and to expanding Argentina's airline connectivity profitably throughout the region. LCCs such as Flybondi, Norwegian, Air Europa, Sky, JetSmart, and others are challenging long-standing transportation relationships in the region and developing new routes for consumers. A set of interlinked questions aims to understand Argentina's changing aviation geography. Comparing O-D data from 1972, 1982, 1996, and 2019, the results indicate a significant reorganization of Argentinas domestic and regional network interactions, with modest adjustments to its global north-south connections. Challenges include outcomes of a recent change in Argentina's government and the long-term impact of the global COVID19 pandemic on the aviation system.     

On the multi-dimensionality and sampling of air transport networks

Complex network theory is a framework increasingly used in the study of air transport networks, thanks to its ability to describe the structures created by networks of flights, and their influence in dynamical processes such as delay propagation. While many works consider only a fraction of the network, created by major airports or airlines, for example, it is not clear if and how such sampling process bias the observed structures and processes. In this contribution, we tackle this problem by studying how some observed topological metrics depend on the way the network is reconstructed, i.e. on the rules used to sample nodes and connections. Both structural and simple dynamical properties are considered, for eight major air networks and different source datasets. Results indicate that using a subset of airports strongly distorts our perception of the network, even when just small ones are discarded; at the same time, considering a subset of airlines yields a better and more stable representation. This allows us to provide some general guidelines on the way airports and connections should be sampled.     

Network competition in the open aviation area

In 2008 the ‘joint open aviation area’ between the US and EU will become reality. It is expected that competition will increase. The reaction of the airlines depends on the possibility to make profits in ‘new’ markets (markets that can now be entered). This, in turn, depends on network characteristics. In this paper we find that full liberalization of international markets by means of a bilateral agreement results in higher welfare than the formation of an alliance. Carriers, however, will also in fully deregulated aviation markets most likely opt for an alliance. This is a result of a built-in competitive effect of hub–spoke networks. Only in markets where the reservation price is very high (e.g. to London Heathrow), hub–spoke airlines may enter a competitive game. Low-cost airlines, which do not operate extensive hub–spoke networks, may find it profitable to enter new markets.     

Liner shipping hub network design in a competitive environment

A mixed integer programming formulation is proposed for hub-and-spoke network design in a competitive environment. It addresses the competition between a newcomer liner service provider and an existing dominating operator, both operating on hub-and-spoke networks. The newcomer company maximizes its market share—which depends on the service time and transportation cost—by locating a predefined number of hubs at candidate ports and designing its network. While general-purpose solvers do not solve instances of even small size, an accelerated Lagrangian method combined with a primal heuristic obtains promising bounds. Our computational experiments on real instances of practical size indicate superiority of our approach.     

Efficiency evaluation of Brazilian airlines operations considering the Covid-19 outbreak

In this paper we evaluate the operational efficiency of the Brazilian airlines considering the novel coronavirus Covid-19 outbreak. This novel coronavirus was first reported end of 2019 in Wuhan, China, however the powerful contamination spread among people forced the World Health Organization to characterize the Covid-19 as a pandemic in March of 2020. Here we analyze the main Brazilian airlines operations response due to lower demand because Covid-19 outbreak in first quarter of 2020 comparing with first quarter of 2019. The analysis here aims to verify the efficiency of airlines in domestic air transport market in Brazil through Multicriteria Data Envelopment Analysis (MCDEA) model. We used MCDEA to avoid limitations of classical DEA models for the case, especially the numbers of decision units and variable. In this paper we used an improvement of the MCDEA model to seek benchmarks considering a dual model all objective functions of MCDEA. The results highlight the challenges for the airlines, due to flight restriction and demand dropping. And also, the evaluation exposes the different company configuration of aircrafts age and network reconfiguration which was reflected by the efficiency difference on the period. The assessment shows the company with a better mix of aircraft models has a leverage on efficiency response due to unpredictable period as the pandemic Covid-19 outbreak.     

Network structure and capacity requirement: The case of China

This paper analyzes capacity requirement by alternative network structures. Based on a simple model, it is concluded that the capacity required under a hub-and-spoke network would be more than twice as large as the capacity required under a fully connected network. In recent years, China has experienced unprecedented growth in the demand for air travel, which has put continuous pressure on the expansion in airport capacity. Still as a developing country, China suffers from insufficient investment in infrastructure. Therefore, given scarce capacity, it may be more efficient for the major air carriers not to adopt the hub-and-spoke network in Chinese domestic markets.     

Network concentration and airport congestion in a post de-regulation context: A case study of Brazil 2000–2010

This paper empirically investigates the main drivers of airline network concentration in an air transport market subject to rapid growth. We consider the Brazilian air transport industry of the 2000s, in which network concentration rapidly increased and was followed by a period of massive flight delays and cancelations, which resulted in the “big blackout” of 2006–2007. We develop an econometric model of network concentration, accounting for demand, cost and competition variables that may affect the propensity of carriers to concentrate flights and passenger connections on a few airports of a network. The main focus of the paper is on the relation between networks leading to the problems of the blackout episode. We investigate the dynamic pattern of the evolution of concentration before and after the abnormal period of operations and find that concentration began to rise at least six quarters before, and persisted at a high level until two quarters after the blackout – and then plunged steeply toward the end of the decade. We believe that our analysis contributes to an improved understanding of the behavior of air transport systems subject to network concentration and congestion. With respect to methodology, we suggest and employ the use of alternative measures of network concentration to check the robustness and validity of our results.     

Multi-port vs. Hub-and-Spoke port calls by containerships

This paper addresses the design of container liner shipping networks taking into consideration container management issues including empty container repositioning. We examine two typical service networks with different ship sizes: multi-port calling by conventional ship size and hub-and-spoke by mega-ship. The entire solution process is performed in two phases: the service network design and container distribution. A wide variety of numerical experiments are conducted for the Asia–Europe and Asia–North America trade lanes. In most scenarios the multi-port calling is superior in terms of total cost, while the hub-and-spoke is more advantageous in the European trade for a costly shipping company.     

A note on how to measure hubbing practices in airline networks

Benefits and costs associated to hubbing practices of airlines are still subject to much debate. In the previous literature, some standard spatial concentration indices have been proposed to measure it. However, we show that these indices are “ill-defined” because they do not take into account the salient characteristic of hubbing: connecting passengers. The purpose of this research is to present a new methodology which avoids the pitfalls of other methods. Our new methodology also analyzes the level of concentration of the connecting passengers studying two different dimensions: hub airports and routes. Finally, we apply our methodology to some US carriers.