Dynamic DEA models with network structure: An application for Iranian airlines

Efficiency estimation of interdependent divisions within a company or assessing the interrelated processes in a production system provides insights for improving the operational performance. Recent developments in network data envelopment analysis (NDEA) models enable decision making units (DMUs) to be informed of inefficient processes within the system. The NDEA model assesses the processes of the system in a specific moment and ignores the dynamic effects within the production processes. Thus, without considering the temporal dimension of production processes, biased efficiency measurement will be obtained that provides misleading information to DMUs. For evaluating the performance of a DMU with interrelated processes during specified multiple periods, this paper proposes a relational dynamic NDEA (DNDEA) model which measures the efficiencies of the system and its internal processes over the time, simultaneously. To illustrate the capability of the proposed model, this study for the first time measures the efficiency of eight Iranian airlines in several periods connected to each other by carry over flows. The actual data is gathered in three periods from 2010 to 2012 and the results are compared with the dynamic DEA and network DEA models in the same time span.     

The impact of environmental variables on the efficiency of Chinese and other non-Chinese airlines

This paper explores the impact of an international focus, the proportion of cargo traffic, and the level of salaries on the operational efficiency of Chinese airlines and other non-Chinese airlines. Data envelopment analysis (DEA) is employed to evaluate the operational efficiency and a bootstrapped truncated regression is applied to explore the impact of environmental variables on efficiency. The results show that an international focus has a negative impact, while the level of salaries has a positive impact. Also, we demonstrate that there is an inverted U-shaped relationship between efficiency and the proportion of cargo traffic.     

Evaluating airline efficiency: An application of Virtual Frontier Network SBM

In this paper, airline efficiency is divided into three stages: Operations Stage, Services Stage and Sales Stage. The new three-stage strategic operating framework of airline efficiency is a modification of existing models. A new model, Virtual Frontier Network SBM, is proposed to evaluate the efficiency of 22 international airlines from 2008 to 2012. The results demonstrate the following: 1. The new model can apply to a new benchmarking airline such as Scandinavian Airlines. 2. Although passenger traffic, cargo traffic and revenue decreased from 2008 to 2009, most airlines’ overall efficiency increased in the period.     

An analysis of profitability of the world’s major airlines

This paper analyses airline profitability through an examination of the changes in their productivity growth and the ability to markup prices above costs. A yearly panel data of 22 major airlines over the 1986–1995 period is used. Despite the fact that the European carriers were subjected to a more rapid rise in input prices and a faster decline in airfares than their North American counterparts, they achieved a faster growth in profitability since the early 1990s thanks to their higher productivity growth caused largely by the increased competition in Europe. Although overall profitability of the industry has improved during the 1990s, there are significant variations across airlines because of their differential capabilities to deal with the increasing competition and input prices.     

Eco-positioning of airlines: Perception versus actual performance

To date there has been little research in air transport into the eco-positioning of airlines, that is, their environmental image relative to other airlines and how actual environmental performance relates to this eco-positioning. This paper identifies the environmental perceptions that passengers hold of twelve airlines and relates these perceptions to airlines' actual environmental performance, using load factors, aircraft age and the atmosfair Airline index as proxies for environmental performance. Based on a survey of over 600 passengers at Liverpool John Lennon Airport, the research analyses air travellers' perception of airlines from an environmental perspective. The results show that while there are significant differences in people's environmental perception of airlines, the eco-positioning of the airlines is not correlated to their actual environmental performance. The results support previous research findings in other industries that in many cases actual performance is less important than communicating environmental messages to the public in creating a superior eco-positioning.     

The economic approach to subsidies for foreign airlines

Many air carriers have challenged each other's financing arrangements, each asserting that the other benefits from substantial subsidies. We argue that the ‘subsidy’ classification is a distraction. Firstly, subsidies are quite difficult to define. Secondly, subsidies are little different in their economic effects to many other policy actions, and should be evaluated by policymakers similarly to these other measures. An economic approach would be to assess whether, in overall cost-benefit terms, a country is harmed by subsidies received by another country's airlines. Even if home airlines lose out, home passengers will gain, and the balance will often be positive. The paper outlines the circumstances under which a country would gain or lose from a subsidy to a foreign airline.     

Hedging jet fuel price risk: The case of U.S. passenger airlines

Jet fuel accounts for a large portion of passenger airlines' operating costs, and airlines' earnings are susceptible to swings in the price of jet fuel. This study uses daily data over the past two decades to determine the minimum variance hedge ratio for airlines wishing to hedge jet fuel price risk with futures, while also establishing the best cross hedging asset. Airlines hedging with futures would create the most effective hedge by using heating oil futures contracts with a 3-month maturity. We also find that beyond the 3-month veil, increased time to maturity makes heating oil less effective as a cross hedge proxy for jet fuel. However, both in-sample analysis and Monte Carlo simulation results with daily data show that none of the 4 cross hedge proxies, including heating oil, can be considered highly effective.     

Malmquist financial efficiency analysis for airlines

This article discusses the financial efficiency of 42 airlines from 25 countries, in 2001 (the year of the September 11 terrorist attack in the United States), and their profitability in the following year. The Malmquist index was used to indicate the airlines’ capital structure changes from 2001 to 2002. The results show airline capital structure management and profitability dynamics following the unexpected event of 2001. The main conclusion is that airlines which moved more intensively to reduce their indebtedness showed improved profitability, given their size, fleet and intangible assets.     

Effect of concentration in airline market on Spanish airport technical efficiency

This paper tries to measure the effect of airline market concentration on airport technical efficiency. With this aim, a Stochastic Frontier Analysis (SFA) is applied, estimating with a one-step procedure technical efficiency and the effect of airlines' market power on that efficiency. Results suggest that when airports are lowly concentrated increasing concentration reduces such inefficiencies. However, this effect practically disappears when airports are highly concentrated. Additionally, the government's policies to improve airports' performance seems to have a positive effect in the short run.     

A cross cultural investigation of airlines service quality through integration of Servqual and the Kano model

This paper examines the service quality attributes of airlines with regard to their effect on customer satisfaction in a cross-cultural context. The applicability of a modified Servqual instrument as a means of measuring customers' perceptions and expectations is explored using respondents from USA and Turkey. The study is unique as it integrates the Servqual scale and the Kano model in a complementary way. The findings reveal that the Servqual gap scores are negative in both USA and Turkey, in all areas of service quality, indicating that customers' perceptions fall far short of their expectations. For the Kano model, it is demonstrated that the general structure of the scale is the same for both countries. However, the two countries differ in certain service quality attributes as far as prioritization. This has implications for the formulation of airline marketing strategies. While some degree of standardization is necessary for certain service elements, especially if the airline is catering for the international market, there are certain service attributes that should be designed to meet local needs and expectations.     

Technical efficiency of mainstream airlines and low-cost carriers: New evidence using bootstrap data envelopment analysis truncated regression

Between 2001 and 2005, the US airline industry faced financial turmoil while the European airline industry entered a period of substantive deregulation. Consequently, this opened up opportunities for low-cost carriers to become more competitive in the market. To assess airline performance and identify the sources of efficiency in the immediate aftermath of these events, we employ a bootstrap data envelopment analysis truncated regression approach. The results suggest that at the time the mainstream airlines needed to significantly reorganize and rescale their operations to remain competitive. In the second-stage analysis, the results indicate that private ownership, status as a low-cost carrier, and improvements in weight load contributed to better organizational efficiency.     

Efficiency of US airlines: A strategic operating model

This paper applies the unoriented DEA network methodology to measure US airlines' performance relative to that of peer airlines and identifies the sources of its inefficiency. The analysis of the results suggests that major US airlines are more efficient than national US airlines in spending operating expenses and gaining operating revenue, but there is no significant difference in their service supply and demand efficiencies.     

Evaluating drivers of profitability for airlines in Latin America: A case study of Copa Airlines

Air Traffic demand in Latin America is expected to double over the next twenty years, yet airline profitability in the region remains highly problematic. The impediments challenging financial prosperity in the continent are numerous and have resulted in prolonged loss-making periods across most Latin American carriers. Breaking with this trend, Copa Airlines has been able to report double-digit net results for several years and recorded 56% of total profits earned by all Latin American carriers in 2016. This research has identified a number of Key Performance Indicators that have underpinned Copa Airlines' financial prosperity through a Product and Organisational Architecture (POA) framework analysis whose results were validated and elaborated upon by the CEO of Copa Airlines. Copa's sustained financial success was attributable to a number of factors. First, its geographical positioning has allowed it to engineer strong connectivity by coupling North and South America through its hub, which is reachable with narrowbodies to nearly all points in the Americas. Second, its low unit cost structure is akin to that of LCCs, operating a single aircraft type with high utilisation. Third, it has a uniquely low market concentration of competitors on its routes and capitalises on this by having a strong schedule with high frequencies together with outstanding punctuality. Fourth, it has a synergistic and fruitful cooperation with its hub airport at Tocumen. Finally it benefits from positive external factors such as a dollarized home economy with high GDP growth, exceptionally low unemployment and inflation rates ring-fenced with security. These pillars can be used as a reference for other Latin based airlines seeking to improve profitability.     

Performance assessment of airlines using range-adjusted measure,strong complementary slackness condition,and discriminant analysis

This study integrates RAM (range-adjusted measure), SCSC (strong complementary slackness condition), and DEA–DA (data envelopment analysis–discriminant analysis) to rank airlines. As conventional DEA models do not fully use all inputs and outputs, they result zero in many multipliers. These sorts of DEA models may yield many efficient decision-making units (DMUs). This decreases the discrimination power of DEA. To overcome this limitation, this study proposes a novel application of RAM–DEA/SCSC along with DA. A case study demonstrates the applicability of our proposed approach.     

Multi-period efficiency and productivity changes in US domestic airlines

This study tracked the static efficiency and dynamic productivity changes of 14 US airlines from 2006 to 2015. Moreover, we estimated the principal economic drivers of the environmental variables to increase the US domestic airlines' efficiency using the double bootstrap regression analysis. The major aspects of this study are as follows: First, network legacy carriers have the highest efficiency, whereas low-cost carriers are lowest. Nonetheless, network legacy carriers still have room to improve scale inefficiency. Second, the fluctuations in technical change, rather than in efficiency change, tended to have greater effect on the fluctuation of Malmquist productivity index for US domestic airlines. Third, M&A between US airlines have both positive and negative effects in terms of efficiency and economies of scale. Fourth, cost environmental factors have a negative effect on US airlines' efficiency, while revenue factor is a positive effect. The results of this study may help US airline industry practitioners to understand the US domestic airline environment from an operator's perspective.     

A productivity comparison of the world's major airlines

This paper measures and compares productivity and unit cost of the world's 23 major airlines using yearly panel data (1986–1993). An extensive effort was expended to put together a reliable database. These data are then used to accomplish the following: first, unit cost per unit of aggregate output is measured and compared. The effect of input price changes on the unit costs are also examined. Second, the ‘gross’ Total Factor Productivity (TFP) is measured and compared. In order to compare true productive efficiency across airlines and over time, a ‘residual’ TFP index is computed after removing effects of the variables beyond managerial control such as average stage length and composition of outputs. Log-linear TFP level, and TFP growth rate regressions are used to accomplish this task. Our results show that:

1. (a) during the sample period (1986–1993), the major European carriers and the carriers in newly industrialized countries in Asia have achieved significantly higher productivity growth than their North American counterparts;

2. (b) as a result, the productivity gap between North American and other carriers have diminished significantly;

3. (c) however, on average, the North American carriers still enjoy higher productive efficiency than the carriers in Asian NICs and European carriers, but the gap is closing very rapidly; and

4. (d) it is observed that, over time, the productive efficiency of carriers competing in the same markets tends to converge.

Finally, Asian NIC carriers clearly enjoy unit cost advantages over other major carriers. Our results show that European aviation liberalization which began in 1987 appears to have produced substantial productivity gains.     

Productivity efficiency analysis of the airlines in China after deregulation

Using data envelopment analysis and the Malmquist productivity index, this paper studies productivity efficiency of various airlines in China after the Chinese government deregulated the aviation industry in 2005. The results show that the productivity efficiency of non-state-owned airlines improves rapidly and eventually exceeds state-owned airlines after the deregulation policy. Among the state-owned airlines, the productivity of the local airlines and their technical changes are better than those of the central airlines.     

An analysis of the greenhouse gas emissions profile of airlines flying the Australian international market

International commercial flights (with the exception of flights between countries in European Union including Iceland, Norway and Liechtenstein) are currently not subject to greenhouse gas emission reduction regulation. To formulate effective and efficiency policy to manage greenhouse gas emissions from air transport, policy makers need to determine the emissions profiles of all airlines currently flying into their country or region. In this paper, we use 2012 data on airlines' aircraft characteristics, passenger load and cargo load (obtained from statistics reported by Australian Government Bureau of Infrastructure, Transport and Regional Economics) to estimate the volume and carbon efficiency on each international route flying to and from Australia. This is the first study to use actual passenger and cargo load data to determine the greenhouse gas (specifically CO₂) efficiency of airlines operating in the Australian international aviation market. Airlines' CO₂ emission profile is dependent on many factors including but not limited to the aircraft used, payload, route taken, weather conditions. Our results reveal that the airlines’ CO₂ emission profile is not only dependent on the aircraft used and the number of passengers but also the amount of cargo on each flight.     

A fully fuzzy network DEA-Range Adjusted Measure model for evaluating airlines efficiency: A case of Iran

Due to the competition among companies, evaluating the performance is one of the most important issues for managers. Data Envelopment Analysis (DEA) - Range Adjusted Measure model (RAM) is one of the non-radial models to evaluate the performance of companies. This paper presents a fully fuzzy network DEA-RAM model for evaluating airlines and extends the network DEA-RAM model in the fully fuzzy framework. First, a network structure is designed for airlines and then, a DEA-RAM model is presented for calculating efficiency scores. To handle uncertainty in data, fully fuzzy approach is considered and finally, a multi-objective network model is proposed to calculate airlines’ efficiencies. To solve the proposed fully fuzzy DEA-RAM model, the lexicographic approach is used and the efficiency scores are reported as interval numbers. To illustrate the capability of the proposed fully fuzzy DEA-RAM model, the actual data of 14 Iranian airlines are gathered and the interval efficiencies of airlines are evaluated.     

Race to the bottom or swimming upstream: Performance analysis of US airlines

Data envelopment analysis is used to examine inter-temporal and peer group airline efficiency. Results for the US for 1985–2006 indicate that airline performance is converging over time. In particular, airlines inter-temporal inefficiency peaked earlier and then converged. Furthermore, using Tobit specifications it is seen that while demand intensity matters less in determining airlines inter-temporal inefficiency, their influence is stronger in determining peer group inefficiency. Block time, a representative of operational factors, tends to negatively impact airlines efficiency by imposing burdens on airline operations. Among the structural cost and revenue factors, fuel cost tends to affect inter-temporal inefficiency more robustly than it does to peer group efficiency. Labor pay tends to reduce inefficiency in case of inter-temporal while increasing peer group inefficiency. The events of September 11th had little or no impact on inter-temporal inefficiency but tended to reduce peer group inefficiency in a significant way. Finally, airlines efficiency tends to be robustly affected by block hours; reducing them increases efficiency.