Alessandro Cento - Academia.edu (original) (raw)

Papers by Alessandro Cento

Research paper thumbnail of Assessment of New Hub-and-Spoke and Point-to-Point Airline Network Configurations

Http Dx Doi Org 10 1080 01441640701322552, 2007

*Università della Valle d'Aosta, Aosta, and CERTeT, Bocconi University, ... more *Università della Valle d'Aosta, Aosta, and CERTeT, Bocconi University, Milan, Italy; **Revenue Management Department, KLM Royal Dutch Airlines, Segrate (MI), Italy; †Department of Spatial Economics, Free University, Amsterdam, the Netherlands Taylor and Francis Ltd ...

Research paper thumbnail of Europ ean ai rl i nes conduct af t e r Septemb er 11t h

This paper analyses the reorganisation that European carriers have implemented after September 11... more This paper analyses the reorganisation that European carriers have implemented after September 11th in the transatlanticflights. We model carriers' conduct as a mixture of short- and long-term goals where the weights depend on firm-specific variables (adjustment costs, financial sit- uation) and subjective expectations on the crisis duration. Data provide som e supp ort to o ur c on jecture s

Research paper thumbnail of Assessment of polycyclic aromatic hydrocarbon concentrations in mussels ( Mytilus galloprovincialis ) from the Western basin of the Mediterranean Sea

Environmental Monitoring and Assessment, 2011

The Mytilos project was carried during the last 3 years (2004)(2005)(2006) in order to evaluate t... more The Mytilos project was carried during the last 3 years (2004)(2005)(2006) in order to evaluate the level of chemical contamination along the coasts of the western basin of the Mediterranean Sea. Active mussel watch consisted of caged (12 weeks) Mytilus galloprovincialis at 123 stations along the Mediterranean coasts of Spain, France, Italy, North Tunisia, Algeria and Morocco. Results indicated total PAHs levels in the range 22-106 μg/kg dry weight. All large towns or industrial areas from all countries of the basin were affected. Analysis of the origin of contamination demonstrated mainly a pyrolytic origin except in some areas such as Maddalena, Napoli, Alger, and Cornigliano (Genova). Statistical analysis of the PAHs accumulation data enabled the characterisation and ranking of each coastal area. The overall results give scientific and technical basis for large-scale monitoring of the PAH contamination in the entire western Mediterranean basin.

Research paper thumbnail of Network competition - the co-existence of hub-and-spoke and point-to-point

Airlines network choices are analysed to describe the co-existence of alternative business models... more Airlines network choices are analysed to describe the co-existence of alternative business models: the full service model based on the hub-and-spoke (HS) system and the low cost model based on point-to-point (PP) system. The analysis is carried on both theoretically and empirically. In the theoretical part, we show that the rise of the low costs business model can be the consequence of a simple two-player game. When two carriers compete in designing their network configurations (HS or PP), asymmetric equilibria emerge, i.e. one carrier will choose HS and the other PP. Full service carriers are stuck to a HS configuration to serve intercontinental destinations, whilst non-flag carriers implement a point-to-point network. In the second part, the recent network evolution in Europe is empirically evaluated by means of different spatial measures of concentration, such as Gini index, Freeman centrality index and Bonacich centrality. In addition, we also provide an airline-specific measure...

Research paper thumbnail of Assessment of polycyclic aromatic hydrocarbon concentrations in mussels (Mytilus galloprovincialis) from the Western basin of the Mediterranean Sea

Environmental monitoring and assessment, 2011

The Mytilos project was carried during the last 3 years (2004-2006) in order to evaluate the leve... more The Mytilos project was carried during the last 3 years (2004-2006) in order to evaluate the level of chemical contamination along the coasts of the western basin of the Mediterranean Sea. Active mussel watch consisted of caged (12 weeks) Mytilus galloprovincialis at 123 stations along the Mediterranean coasts of Spain, France, Italy, North Tunisia, Algeria and Morocco. Results indicated total PAHs levels in the range 22-106 μg/kg dry weight. All large towns or industrial areas from all countries of the basin were affected. Analysis of the origin of contamination demonstrated mainly a pyrolytic origin except in some areas such as Maddalena, Napoli, Alger, and Cornigliano (Genova). Statistical analysis of the PAHs accumulation data enabled the characterisation and ranking of each coastal area. The overall results give scientific and technical basis for large-scale monitoring of the PAH contamination in the entire western Mediterranean basin.

Research paper thumbnail of Short- and Long-Term Reaction of European Airlines to Exogenous Demand Shifts

Advances in Spatial Science, 2005

... This process is usually organised on three levels: 1) strategic planning: alli-ances, buying/... more ... This process is usually organised on three levels: 1) strategic planning: alli-ances, buying/selling new aircraft, anticipating new routes, usually every 1–3 years; 2) tactical ... In addition, Gillen and Lall (2003) examine shock transmission in the airline industry after Septem-ber 11. ...

Research paper thumbnail of Second-Degree Price Discrimination and Inter-Group Effects in Airline Routes between European Cities

SSRN Electronic Journal, 2000

This paper presents a model of second-degree price discrimination and inter-group effects to desc... more This paper presents a model of second-degree price discrimination and inter-group effects to describe the full-service pricing behaviour in the passenger aviation market. Consumer heterogeneity is assumed on both a horizontal and a vertical dimension, while various distinct market structures, some of which include low-cost carriers (LCCs), are considered. In the theoretical model framework, we derive that the rivalry between full-service carriers (FSCs) reduces fare differences between the business and leisure segments. Furthermore, the presence of LCCs increases fare gaps between leisure and business travellers, and it also induces FSCs to decrease fares in the leisure segment and eventually to increase them in the business one. This last outcome emerges from a change in passenger arrangements caused by inter-group effects. In our empirical analysis, we use data on published airfares of Lufthansa, British Airways, KLM and Alitalia for the main city-pairs from Italy to Germany, the UK and the Netherlands. Our results show that the empirical results provide support for our theoretical propositions.

Research paper thumbnail of The Entry of Low-Cost Airlines: Price Competition in the European Airline Market

SSRN Electronic Journal, 2000

... Page 3. 1 The Entry of Low-Cost Airlines: Price Competition in the European Airline Market Ma... more ... Page 3. 1 The Entry of Low-Cost Airlines: Price Competition in the European Airline Market Marco ALDERIGHI, CERTeT - Bocconi University, Milan, Italy e-mail: marco.alderighi@uni-bocconi. it ... prefer to buy from firm L and others from firm R, S or M. In other words, consumers¶ ...

Research paper thumbnail of Network Measures in Civil Air Transport: A Case Study of Lufthansa

Lecture Notes in Economics and Mathematical Systems, 2009

... In recent years, we have seen several new trends, in particular, the rise of hub-and-spoke sy... more ... In recent years, we have seen several new trends, in particular, the rise of hub-and-spoke systems in liberalized networks, the emergence of dynamic adjust-ments to new competitive conditions and the increase in complexity in international networks. ...

Research paper thumbnail of European Airlines Conduct after September 11th

This paper analyses the network reorganisation that European carriers have implemented after Sept... more This paper analyses the network reorganisation that European carriers have implemented after September 11th in the transatlantic flights. We model carriers' conduct as a mixture of short- and long-term goals where the weights depend on firm-specific variables (adjustment costs, financial situation) and subjective expectations on the crisis duration. Data provide some support to our conjectures that high adjustment costs, induce low reaction to the demand fall and that a bad financial situation shifts the carries attention to short-term profitability. Finally, the analysis of the composition of short- and long-term reaction provides some insights into the carriers' perspectives of the crisis duration.

Research paper thumbnail of Assessment of New Hub‐and‐Spoke and Point‐to‐Point Airline Network Configurations

Transport Reviews, 2007

*Università della Valle d'Aosta, Aosta, and CERTeT, Bocconi University, ... more *Università della Valle d'Aosta, Aosta, and CERTeT, Bocconi University, Milan, Italy; **Revenue Management Department, KLM Royal Dutch Airlines, Segrate (MI), Italy; †Department of Spatial Economics, Free University, Amsterdam, the Netherlands Taylor and Francis Ltd ...

Research paper thumbnail of Competition in the European aviation market: the entry of low-cost airlines

Journal of Transport Geography, 2012

ABSTRACT This paper investigates the price-setting behavior of full-service airlines in the Europ... more ABSTRACT This paper investigates the price-setting behavior of full-service airlines in the European passenger aviation market. We develop a model of airline competition, which accommodates various market structures, some of which include low-cost players. Using data on published airfares of Lufthansa, British Airways, Alitalia and KLM for the main city-pairs from Italy to the rest of Europe, our empirical findings substantially confirm the propositions of the theoretical model. We find that competition among full-service carriers appears to affect the price levels of the business and the leisure segments asymmetrically: there are small reductions in the leisure segments and significant reductions in the business segment of the aviation market. In contrast, competition with low-cost carriers reduces both the business and leisure fares of full-service carriers quite uniformly, with an emphasis on the mid-segment fares.

Research paper thumbnail of A large scale survey of trace metal levels in coastal waters of the Western Mediterranean basin using caged mussels (Mytilus galloprovincialis)

Journal of Environmental Monitoring, 2011

Within the context of the MYTILOS project, a large-scale assessment of trace metal (Hg, Cd, Pb an... more Within the context of the MYTILOS project, a large-scale assessment of trace metal (Hg, Cd, Pb and Ni) content in caged mussels Mytilus galloprovincialis was performed along the coasts of the Western Mediterranean Sea. Caged mussels were deployed for 12 weeks at 122 sites located in Alborán, North-Western, South-Western and Tyrrhenian sub-basins. After recovery on site, metal contents were measured in whole mussel tissue. In order to facilitate interregional comparison, linear regression models were used for normalisation of metal concentrations to condition index. Although for some metals significant differences in mean concentrations were found between sub-basins, levels obtained in most of the sites were low or moderate and they might be considered baseline concentrations. Overall, sites impacted by run-off from land mineralised areas and industrial activities displayed highest concentrations, but also some few sites considered little-influenced by human activities showed high concentrations of some metals. Results from this study confirm that the use of caged mussels is a suitable tool for characterising trace metal status of coastal water bodies in order to support policy makers in establishing a regional strategy, particularly with regard to the EU Marine Strategy Directive.

Research paper thumbnail of European airlines conduct after September 11

Journal of Air Transport Management, 2004

This paper analyses the reorganisation that European carriers have implemented after September 11... more This paper analyses the reorganisation that European carriers have implemented after September 11th in the transatlantic flights. We model carriers' conduct as a mixture of short-and long-term goals where the weights depend on firm-specific variables (adjustment costs, financial situation) and subjective expectations on the crisis duration. Data provide som e supp ort to o ur c on jecture s that high adjustm ent costs in duce low fl exibility and a fo cus o n th e lo ng-term ; and that a bad fi nancial situation shifts the carries attention to short-term. Finally, the analysis of the com p osition o f s hort-a nd long-term re ac tion provid es som e insights into the carriers' perspectives of the crisis duration. Keywords: Eu rop ean Airlin e I ndustry, Dyn am ic O ligop oly, C osts o f Adjustment, Crisis. * The authors would like to thank participants of the 2002 NECTAR meeting and the seminar participants at the University of Lugano and the University Bocconi for comments on an erlier draft. This paper benefited from the comments of Silvio Contessi, Rosario Dell'Aquila, Rico Maggi, Peter Nijkamp and Piet Rietveld. The authors would like to thank KLM Royal D u tch A ir lin e s fo r p r ov i d in g d a t a a n d s u p p o r t. T h e a u th o r s ' o p in io n d o e s n o t n e c e s s a r y r e fl ec t th e K L M offi cia l v ie w p o ints . NOTE: Publication forthcoming on the Journal of Air Transport Management

Research paper thumbnail of Network competition—the coexistence of hub-and-spoke and point-to-point systems

Journal of Air Transport Management, 2005

The paper identifies conditions under which asymmetric equilibria may exist when carriers compete... more The paper identifies conditions under which asymmetric equilibria may exist when carriers compete in designing their network configurations in a game-theoretical framework. Two carriers are assumed here, which are allowed to play three different strategies: point-to-point, hub-and-spoke (HS) or multi-hub. We find two main stable outcomes, which depend on the size of the internal market. First, when the internal markets are small, point-to-point network strategies are played by both carriers, while for a specific subset of parameters a collusive equilibrium in a hub-and-spoke configuration can be derived. Second, when the size of the internal markets is large, asymmetric configurations, where one carrier chooses a hub-and-spoke strategy and the other chooses a point-to-point strategy, are the only stable equilibria. The result can be used to describe the co-existence of alternative business models that have recently emerged in the aviation industry: the established full-service model based on the huband-spoke system and the recent low-cost model based on the point-to-point system.

Research paper thumbnail of A case study of pricing strategies in European airline markets: The London – Amsterdam route

Journal of Air Transport Management, 2011

ABSTRACT We collect data on published fares for the route London-Amsterdam to shed some light on ... more ABSTRACT We collect data on published fares for the route London-Amsterdam to shed some light on the pricing practices of low-cost and legacy carriers, when operating in a large and crowded market. We investigate the reach of two strategies of segmentation involving the time before departure the ticket has been bought (inter-temporal segmentation) and the duration of the stay (implicit segmentation). Some notable results come into view from the analysis. First, inter-temporal price discrimination emerges as a leading aspect of all carriers pricing strategy. Second, the two legacy carriers (British Airways and KLM) differ in their use of stay restrictions (e.g. minimum number of days to stay at the destinations, Saturday-night stay-over, etc..). British Airways does not assign a specific role to the duration of the stay, while KLM uses these travelling rules more extensively in its price setting process (the tourist travellers appear to enjoy discounts of about 50% relative to short stay business travellers).

Research paper thumbnail of Assessment of polycyclic aromatic hydrocarbon contamination of the Bílina River (Czech Republic) using passive water samplers and fish biliary metabolites

Acta Veterinaria Brno, 2011

Research paper thumbnail of Western Mediterranean coastal waters—Monitoring PCBs and pesticides accumulation in Mytilus galloprovincialis by active mussel watching: the Mytilos project

Journal of Environmental Monitoring, 2010

In order to evaluate the contamination levels in the Western Mediterranean basin, the active muss... more In order to evaluate the contamination levels in the Western Mediterranean basin, the active mussel watch methodology has been applied. This methodology consists of mussel transplantation (Mytilus galloprovincialis) from non impacted areas to selected coastal areas, characterised by potential impact from the continent due to contaminating sources. The areas of interest were selected along the entire coastal development of the Western Mediterranean sea, 122 sites in total. The time of mussel caging exposure was 12 weeks. The project was co-financed in the frame of the Interreg IIIB Meddoc Programme, aimed at determining the overall chemical quality of the Mediterranean sea, consistent with the Water Framework Directive 2000/60. Several partners representative of the coastal Mediterranean Countries were involved in the Project, with the purpose of building up a common surveillance network, adopting shared methodologies. In this paper we present the results of three yearly monitoring campaigns (2004, 2005, 2006) carried out along the coasts of Italy, France, Spain, Morocco, Algeria and Tunisia, including the coastal environment of Baleares, Sicily, Sardinia and Corsica. The contamination levels of Pesticides (DDT and its metabolites, Hexachlorocyclohexane isomers and ) and Polychlorinated biphenyls, are reported and discussed. Statistical elaborations performed on the original data set were mainly aimed at validating the raw sample distributions, by means of the Johnson method. Both DD and PCB species frequency distributions have been approximated to appropriate theoretical distributions, belonging to the Log-normal and Bounded families. By integrating the related Probability Density Functions (p.d.f.), different accumulation values for DDT, DDD and DDE and PCB species have been estimated, corresponding to fixed percentage points of the area under the respective curves. By choosing appropriate probability level boundaries (33rd and 66th percentile), different regional zones have been ranked in terms of low, medium and high accumulation for Pesticides and PCBs.

Research paper thumbnail of Assessment of New Hub-and-Spoke and Point-to-Point Airline Network Configurations

Http Dx Doi Org 10 1080 01441640701322552, 2007

*Università della Valle d'Aosta, Aosta, and CERTeT, Bocconi University, ... more *Università della Valle d'Aosta, Aosta, and CERTeT, Bocconi University, Milan, Italy; **Revenue Management Department, KLM Royal Dutch Airlines, Segrate (MI), Italy; †Department of Spatial Economics, Free University, Amsterdam, the Netherlands Taylor and Francis Ltd ...

Research paper thumbnail of Europ ean ai rl i nes conduct af t e r Septemb er 11t h

This paper analyses the reorganisation that European carriers have implemented after September 11... more This paper analyses the reorganisation that European carriers have implemented after September 11th in the transatlanticflights. We model carriers' conduct as a mixture of short- and long-term goals where the weights depend on firm-specific variables (adjustment costs, financial sit- uation) and subjective expectations on the crisis duration. Data provide som e supp ort to o ur c on jecture s

Research paper thumbnail of Assessment of polycyclic aromatic hydrocarbon concentrations in mussels ( Mytilus galloprovincialis ) from the Western basin of the Mediterranean Sea

Environmental Monitoring and Assessment, 2011

The Mytilos project was carried during the last 3 years (2004)(2005)(2006) in order to evaluate t... more The Mytilos project was carried during the last 3 years (2004)(2005)(2006) in order to evaluate the level of chemical contamination along the coasts of the western basin of the Mediterranean Sea. Active mussel watch consisted of caged (12 weeks) Mytilus galloprovincialis at 123 stations along the Mediterranean coasts of Spain, France, Italy, North Tunisia, Algeria and Morocco. Results indicated total PAHs levels in the range 22-106 μg/kg dry weight. All large towns or industrial areas from all countries of the basin were affected. Analysis of the origin of contamination demonstrated mainly a pyrolytic origin except in some areas such as Maddalena, Napoli, Alger, and Cornigliano (Genova). Statistical analysis of the PAHs accumulation data enabled the characterisation and ranking of each coastal area. The overall results give scientific and technical basis for large-scale monitoring of the PAH contamination in the entire western Mediterranean basin.

Research paper thumbnail of Network competition - the co-existence of hub-and-spoke and point-to-point

Airlines network choices are analysed to describe the co-existence of alternative business models... more Airlines network choices are analysed to describe the co-existence of alternative business models: the full service model based on the hub-and-spoke (HS) system and the low cost model based on point-to-point (PP) system. The analysis is carried on both theoretically and empirically. In the theoretical part, we show that the rise of the low costs business model can be the consequence of a simple two-player game. When two carriers compete in designing their network configurations (HS or PP), asymmetric equilibria emerge, i.e. one carrier will choose HS and the other PP. Full service carriers are stuck to a HS configuration to serve intercontinental destinations, whilst non-flag carriers implement a point-to-point network. In the second part, the recent network evolution in Europe is empirically evaluated by means of different spatial measures of concentration, such as Gini index, Freeman centrality index and Bonacich centrality. In addition, we also provide an airline-specific measure...

Research paper thumbnail of Assessment of polycyclic aromatic hydrocarbon concentrations in mussels (Mytilus galloprovincialis) from the Western basin of the Mediterranean Sea

Environmental monitoring and assessment, 2011

The Mytilos project was carried during the last 3 years (2004-2006) in order to evaluate the leve... more The Mytilos project was carried during the last 3 years (2004-2006) in order to evaluate the level of chemical contamination along the coasts of the western basin of the Mediterranean Sea. Active mussel watch consisted of caged (12 weeks) Mytilus galloprovincialis at 123 stations along the Mediterranean coasts of Spain, France, Italy, North Tunisia, Algeria and Morocco. Results indicated total PAHs levels in the range 22-106 μg/kg dry weight. All large towns or industrial areas from all countries of the basin were affected. Analysis of the origin of contamination demonstrated mainly a pyrolytic origin except in some areas such as Maddalena, Napoli, Alger, and Cornigliano (Genova). Statistical analysis of the PAHs accumulation data enabled the characterisation and ranking of each coastal area. The overall results give scientific and technical basis for large-scale monitoring of the PAH contamination in the entire western Mediterranean basin.

Research paper thumbnail of Short- and Long-Term Reaction of European Airlines to Exogenous Demand Shifts

Advances in Spatial Science, 2005

... This process is usually organised on three levels: 1) strategic planning: alli-ances, buying/... more ... This process is usually organised on three levels: 1) strategic planning: alli-ances, buying/selling new aircraft, anticipating new routes, usually every 1–3 years; 2) tactical ... In addition, Gillen and Lall (2003) examine shock transmission in the airline industry after Septem-ber 11. ...

Research paper thumbnail of Second-Degree Price Discrimination and Inter-Group Effects in Airline Routes between European Cities

SSRN Electronic Journal, 2000

This paper presents a model of second-degree price discrimination and inter-group effects to desc... more This paper presents a model of second-degree price discrimination and inter-group effects to describe the full-service pricing behaviour in the passenger aviation market. Consumer heterogeneity is assumed on both a horizontal and a vertical dimension, while various distinct market structures, some of which include low-cost carriers (LCCs), are considered. In the theoretical model framework, we derive that the rivalry between full-service carriers (FSCs) reduces fare differences between the business and leisure segments. Furthermore, the presence of LCCs increases fare gaps between leisure and business travellers, and it also induces FSCs to decrease fares in the leisure segment and eventually to increase them in the business one. This last outcome emerges from a change in passenger arrangements caused by inter-group effects. In our empirical analysis, we use data on published airfares of Lufthansa, British Airways, KLM and Alitalia for the main city-pairs from Italy to Germany, the UK and the Netherlands. Our results show that the empirical results provide support for our theoretical propositions.

Research paper thumbnail of The Entry of Low-Cost Airlines: Price Competition in the European Airline Market

SSRN Electronic Journal, 2000

... Page 3. 1 The Entry of Low-Cost Airlines: Price Competition in the European Airline Market Ma... more ... Page 3. 1 The Entry of Low-Cost Airlines: Price Competition in the European Airline Market Marco ALDERIGHI, CERTeT - Bocconi University, Milan, Italy e-mail: marco.alderighi@uni-bocconi. it ... prefer to buy from firm L and others from firm R, S or M. In other words, consumers¶ ...

Research paper thumbnail of Network Measures in Civil Air Transport: A Case Study of Lufthansa

Lecture Notes in Economics and Mathematical Systems, 2009

... In recent years, we have seen several new trends, in particular, the rise of hub-and-spoke sy... more ... In recent years, we have seen several new trends, in particular, the rise of hub-and-spoke systems in liberalized networks, the emergence of dynamic adjust-ments to new competitive conditions and the increase in complexity in international networks. ...

Research paper thumbnail of European Airlines Conduct after September 11th

This paper analyses the network reorganisation that European carriers have implemented after Sept... more This paper analyses the network reorganisation that European carriers have implemented after September 11th in the transatlantic flights. We model carriers' conduct as a mixture of short- and long-term goals where the weights depend on firm-specific variables (adjustment costs, financial situation) and subjective expectations on the crisis duration. Data provide some support to our conjectures that high adjustment costs, induce low reaction to the demand fall and that a bad financial situation shifts the carries attention to short-term profitability. Finally, the analysis of the composition of short- and long-term reaction provides some insights into the carriers' perspectives of the crisis duration.

Research paper thumbnail of Assessment of New Hub‐and‐Spoke and Point‐to‐Point Airline Network Configurations

Transport Reviews, 2007

*Università della Valle d'Aosta, Aosta, and CERTeT, Bocconi University, ... more *Università della Valle d'Aosta, Aosta, and CERTeT, Bocconi University, Milan, Italy; **Revenue Management Department, KLM Royal Dutch Airlines, Segrate (MI), Italy; †Department of Spatial Economics, Free University, Amsterdam, the Netherlands Taylor and Francis Ltd ...

Research paper thumbnail of Competition in the European aviation market: the entry of low-cost airlines

Journal of Transport Geography, 2012

ABSTRACT This paper investigates the price-setting behavior of full-service airlines in the Europ... more ABSTRACT This paper investigates the price-setting behavior of full-service airlines in the European passenger aviation market. We develop a model of airline competition, which accommodates various market structures, some of which include low-cost players. Using data on published airfares of Lufthansa, British Airways, Alitalia and KLM for the main city-pairs from Italy to the rest of Europe, our empirical findings substantially confirm the propositions of the theoretical model. We find that competition among full-service carriers appears to affect the price levels of the business and the leisure segments asymmetrically: there are small reductions in the leisure segments and significant reductions in the business segment of the aviation market. In contrast, competition with low-cost carriers reduces both the business and leisure fares of full-service carriers quite uniformly, with an emphasis on the mid-segment fares.

Research paper thumbnail of A large scale survey of trace metal levels in coastal waters of the Western Mediterranean basin using caged mussels (Mytilus galloprovincialis)

Journal of Environmental Monitoring, 2011

Within the context of the MYTILOS project, a large-scale assessment of trace metal (Hg, Cd, Pb an... more Within the context of the MYTILOS project, a large-scale assessment of trace metal (Hg, Cd, Pb and Ni) content in caged mussels Mytilus galloprovincialis was performed along the coasts of the Western Mediterranean Sea. Caged mussels were deployed for 12 weeks at 122 sites located in Alborán, North-Western, South-Western and Tyrrhenian sub-basins. After recovery on site, metal contents were measured in whole mussel tissue. In order to facilitate interregional comparison, linear regression models were used for normalisation of metal concentrations to condition index. Although for some metals significant differences in mean concentrations were found between sub-basins, levels obtained in most of the sites were low or moderate and they might be considered baseline concentrations. Overall, sites impacted by run-off from land mineralised areas and industrial activities displayed highest concentrations, but also some few sites considered little-influenced by human activities showed high concentrations of some metals. Results from this study confirm that the use of caged mussels is a suitable tool for characterising trace metal status of coastal water bodies in order to support policy makers in establishing a regional strategy, particularly with regard to the EU Marine Strategy Directive.

Research paper thumbnail of European airlines conduct after September 11

Journal of Air Transport Management, 2004

This paper analyses the reorganisation that European carriers have implemented after September 11... more This paper analyses the reorganisation that European carriers have implemented after September 11th in the transatlantic flights. We model carriers' conduct as a mixture of short-and long-term goals where the weights depend on firm-specific variables (adjustment costs, financial situation) and subjective expectations on the crisis duration. Data provide som e supp ort to o ur c on jecture s that high adjustm ent costs in duce low fl exibility and a fo cus o n th e lo ng-term ; and that a bad fi nancial situation shifts the carries attention to short-term. Finally, the analysis of the com p osition o f s hort-a nd long-term re ac tion provid es som e insights into the carriers' perspectives of the crisis duration. Keywords: Eu rop ean Airlin e I ndustry, Dyn am ic O ligop oly, C osts o f Adjustment, Crisis. * The authors would like to thank participants of the 2002 NECTAR meeting and the seminar participants at the University of Lugano and the University Bocconi for comments on an erlier draft. This paper benefited from the comments of Silvio Contessi, Rosario Dell'Aquila, Rico Maggi, Peter Nijkamp and Piet Rietveld. The authors would like to thank KLM Royal D u tch A ir lin e s fo r p r ov i d in g d a t a a n d s u p p o r t. T h e a u th o r s ' o p in io n d o e s n o t n e c e s s a r y r e fl ec t th e K L M offi cia l v ie w p o ints . NOTE: Publication forthcoming on the Journal of Air Transport Management

Research paper thumbnail of Network competition—the coexistence of hub-and-spoke and point-to-point systems

Journal of Air Transport Management, 2005

The paper identifies conditions under which asymmetric equilibria may exist when carriers compete... more The paper identifies conditions under which asymmetric equilibria may exist when carriers compete in designing their network configurations in a game-theoretical framework. Two carriers are assumed here, which are allowed to play three different strategies: point-to-point, hub-and-spoke (HS) or multi-hub. We find two main stable outcomes, which depend on the size of the internal market. First, when the internal markets are small, point-to-point network strategies are played by both carriers, while for a specific subset of parameters a collusive equilibrium in a hub-and-spoke configuration can be derived. Second, when the size of the internal markets is large, asymmetric configurations, where one carrier chooses a hub-and-spoke strategy and the other chooses a point-to-point strategy, are the only stable equilibria. The result can be used to describe the co-existence of alternative business models that have recently emerged in the aviation industry: the established full-service model based on the huband-spoke system and the recent low-cost model based on the point-to-point system.

Research paper thumbnail of A case study of pricing strategies in European airline markets: The London – Amsterdam route

Journal of Air Transport Management, 2011

ABSTRACT We collect data on published fares for the route London-Amsterdam to shed some light on ... more ABSTRACT We collect data on published fares for the route London-Amsterdam to shed some light on the pricing practices of low-cost and legacy carriers, when operating in a large and crowded market. We investigate the reach of two strategies of segmentation involving the time before departure the ticket has been bought (inter-temporal segmentation) and the duration of the stay (implicit segmentation). Some notable results come into view from the analysis. First, inter-temporal price discrimination emerges as a leading aspect of all carriers pricing strategy. Second, the two legacy carriers (British Airways and KLM) differ in their use of stay restrictions (e.g. minimum number of days to stay at the destinations, Saturday-night stay-over, etc..). British Airways does not assign a specific role to the duration of the stay, while KLM uses these travelling rules more extensively in its price setting process (the tourist travellers appear to enjoy discounts of about 50% relative to short stay business travellers).

Research paper thumbnail of Assessment of polycyclic aromatic hydrocarbon contamination of the Bílina River (Czech Republic) using passive water samplers and fish biliary metabolites

Acta Veterinaria Brno, 2011

Research paper thumbnail of Western Mediterranean coastal waters—Monitoring PCBs and pesticides accumulation in Mytilus galloprovincialis by active mussel watching: the Mytilos project

Journal of Environmental Monitoring, 2010

In order to evaluate the contamination levels in the Western Mediterranean basin, the active muss... more In order to evaluate the contamination levels in the Western Mediterranean basin, the active mussel watch methodology has been applied. This methodology consists of mussel transplantation (Mytilus galloprovincialis) from non impacted areas to selected coastal areas, characterised by potential impact from the continent due to contaminating sources. The areas of interest were selected along the entire coastal development of the Western Mediterranean sea, 122 sites in total. The time of mussel caging exposure was 12 weeks. The project was co-financed in the frame of the Interreg IIIB Meddoc Programme, aimed at determining the overall chemical quality of the Mediterranean sea, consistent with the Water Framework Directive 2000/60. Several partners representative of the coastal Mediterranean Countries were involved in the Project, with the purpose of building up a common surveillance network, adopting shared methodologies. In this paper we present the results of three yearly monitoring campaigns (2004, 2005, 2006) carried out along the coasts of Italy, France, Spain, Morocco, Algeria and Tunisia, including the coastal environment of Baleares, Sicily, Sardinia and Corsica. The contamination levels of Pesticides (DDT and its metabolites, Hexachlorocyclohexane isomers and ) and Polychlorinated biphenyls, are reported and discussed. Statistical elaborations performed on the original data set were mainly aimed at validating the raw sample distributions, by means of the Johnson method. Both DD and PCB species frequency distributions have been approximated to appropriate theoretical distributions, belonging to the Log-normal and Bounded families. By integrating the related Probability Density Functions (p.d.f.), different accumulation values for DDT, DDD and DDE and PCB species have been estimated, corresponding to fixed percentage points of the area under the respective curves. By choosing appropriate probability level boundaries (33rd and 66th percentile), different regional zones have been ranked in terms of low, medium and high accumulation for Pesticides and PCBs.