2,285 research outputs found

    An Assessment on the Cost Structure of the UK Airport Industry: Ownership Outcomes and Long Run Cost Economies

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    In this paper we analyze the cost structure of the UK airport industry by estimating a variable cost function for the period 1994-2005. Overall results suggest that the long run average costs curve is U-shaped: it decreases until passenger traffic reaches approximately five millions, it remains flat over the range between five and fourteen million passengers and afterwards it starts to increase. Moreover, our findings provide evidence consistent with the existence of some degree of overcapitalization for the largest regulated airports. Finally, we analyze whether different forms of ownership entail cost differentials across airports and we find that privately owned airports are characterized by lower costs with respect to public and mixed ones, although cost differentials shrank over time as public and mixed airports improved their rate of cost reduction. Main results are robust to unobserved heterogeneity at the airport or market level and to possible endogeneity biases. Possible regulatory and policy implications of these results are also discussed.scale economies, public ownership, airports

    And Yet they Co-Move! Public Capital and Productivity in OECD: A Panel Cointegration Analysis with Cross-Section Dependence

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    In this paper we add to the debate on the public capital - productivity link by exploiting very recent developments in the panel time series literature that take into account cross sectional correlation in non-stationary panels. In particular we evaluate the productive effect of public capital by estimating various production functions for a panel of 21 OECD countries over the period 1975-2002. We find strong evidence of common factors that drive the cointegration relationship among variables; moreover, our results suggest a public capital elasticity of GDP in the range 0.05-0.15, depending on model specification. Results are robust to the evidence of spillovers from public capital investments in other countries and to controlling for other productivity determinants like human capital, the stock of patents and R&D capital.Public capital; Productivity; Panel Cointegration; Cross-section Dependence.

    Cost Inefficiency in the English and Welsh Water Industry: An Heteroskedastic Stochastic Cost Frontier Approach.

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    In this study we analyze the evolution of operating cost inefficiency for the English and Welsh water industry over the period 1995-2001 by estimating an heteroskedastic stochastic variable cost frontier. The main aim of this paper is to provide an overall picture of the industry cost inefficiency, as we consider both the water and sewerage companies and the smaller water only companies. The main results of this paper are that industry operating cost inefficiency has decreased over the sample period and that inefficiency differentials among firms have steadily narrowed. This pattern of inefficiency might have been generated by the incentives provided by comparative and capital market competition which became fully operative after the 1994 price review.

    The Appropriateness of the Poolability Assumption for Multiproduct Technologies: Evidence from the English Water and Sewerage Utilities

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    The empirical literature on the cost structure of multiproduct firms (e.g., public utilities providing in combination gas, water, and electricity) traditionally assumes a common technology across different products and stages of production, letting the issue of poolability unexplored. The appropriateness of this assumption is tested here by estimating a General cost function for samples of UK specialized and sewerage-diversified water utilities. The results show the existence of both aggregate scale economies and diseconomies of scope; more interestingly, the hypothesis that the two groups of water companies share the same technological parameters is rejected. Given the implications of this finding in terms of optimal industry configuration and possible restructuring policies (e.g., mergers and/or divestitures), our test suggests caution in pooling samples when undertaking empirical studies on data which refer to multiproduct technologies.Multiproduct technologies; Water and sewerage utilities; Poolability; General cost function

    Cost Inefficiency in the English and Welsh Water Industry: An Heteroskedastic Stochastic Cost Frontier Approach.

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    In this study we analyze the evolution of operating cost inefficiency for the English and Welsh water industry over the period 1995-2001 by estimating an heteroskedastic stochastic variable cost frontier. The main aim of this paper is to provide an overall picture of the industry cost inefficiency, as we consider both the water and sewerage companies and the smaller water only companies. The main results of this paper are that industry operating cost inefficiency has decreased over the sample period and that inefficiency differentials among firms have steadily narrowed. This pattern of inefficiency might have been generated by the incentives provided by comparative and capital market competition which became fully operative after the 1994 price review

    An explorative study on robotics for supporting children with Autism Spectrum Disorder during clinical procedures

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    This short report presents a small-scale explorative study about children with Autism Spectrum Disorder (ASD) interaction with robots during clinical interactions. This is part of an ongoing project, which aims at defining a robotic service for supporting children with developmental disabilities and increase the efficiency of routine procedures that may create distress, e.g.having blood taken or an orthopaedic plaster cast applied. Five children with confirmed diagnoses of ASD interacted with two social robots: the small humanoid NAO and the pet-like MiRo. The encounters mixed play activities with a simulated clinical procedure. We included parents/carers in the interaction to ensure the child was comfortable and at ease. The results of video analysis and parents' feedback confirm possible benefits of the physical presence of robots to reduce children’s anxiety and increase compliance with instructions. Parents/carers convincingly support the introduction of robots in hospital procedures to their help children

    Calabi-Yau cones from contact reduction

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    We consider a generalization of Einstein-Sasaki manifolds, which we characterize in terms both of spinors and differential forms, that in the real analytic case corresponds to contact manifolds whose symplectic cone is Calabi-Yau. We construct solvable examples in seven dimensions. Then, we consider circle actions that preserve the structure, and determine conditions for the contact reduction to carry an induced structure of the same type. We apply this construction to obtain a new hypo-contact structure on S^2\times T^3.Comment: 30 pages; v2: typos corrected, presentation improved, one reference added. To appear in Ann. Glob. Analysis and Geometr

    Alcune riflessioni sulla pratica regolatoria, con riferimento ad alcuni settori dell’industria dei trasporti

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    La regolazione dei mercati rappresenta un elemento fondamentale per il raggiungimento di un’organizzazione più efficiente del sistema dei trasporti insieme ad una distribuzione equa dei vantaggi derivanti dallo stesso. In tale ottica la tutela del consumatore, le norme legate alla qualità e alla sicurezza dei beni e servizi scambiati su un mercato e una consona valutazione delle esternalità sono solo alcuni degli elementi di criticità di cui il regolatore dovrebbe tenere conto. In molti paesi, a partire dagli anni ’80, il settore dei trasporti è stato coinvolto dal processo di privatizzazioni e liberalizzazioni che ha interessato molte public utilities e che ha portato, in particolare, alla creazione di mercati regolati in cui le infrastrutture sono tipicamente gestite in concessione, mentre i servizi, laddove non sia possibile l’introduzione di forme di concorrenza, vengono invece regolamentati e le tariffe determinate secondo regole pre-definite. Nel corso del tempo alcune forme di regolazione tariffaria sembrano essersi imposte senza che la loro adozione nel caso di un particolare settore sia stata adeguatamente valutata alla luce delle caratteristiche economico-tecnologiche del settore stesso. Lo studio qui proposto si prefigge di effettuare un confronto tra i due principali metodi di regolamentazione tariffaria (price cap e regolazione del tasso di rendimento, RoR) tipicamente applicati nei settori altamente regolati, in cui la concorrenza è limitata per motivi tecnici o legati alla sicurezza. L’articolo è organizzato come segue. Il primo paragrafo è dedicato ad una breve discussione della letteratura, mentre nel secondo paragrafo vengono analizzate criticamente le principali caratteristiche dei metodi di regolazione tariffaria ispirati al price cap e al RoR. Quindi, nel terzo paragrafo viene analizzato, alla luce della discussione teorica sviluppata precedentemente, il caso di due diversi settori dei trasporti (autostrade e ormeggio) regolati in Italia con metodi di tipo price cap e RoR. Infine,il quarto paragrafo è dedicato alle conclusioni e alla discussione di possibili sviluppi futuri della ricerca

    Quadrupole scan emittance measurements for the ELI-NP compton gamma source

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    The high brightness electron LINAC of the Compton Gamma Source at the ELI Nuclear Physics facility in Roma- nia is accelerating a train of 32 bunches with a nominal total charge of 250 pC and nominal spacing of 16 ns . To achieve the design gamma flux, all the bunches along the train must have the designed Twiss parameters. Beam sizes are mea- sured with optical transition radiation monitors, allowing a quadrupole scan for Twiss parameters measurements. Since focusing the whole bunch train on the screen may lead to permanent screen damage, we investigate non-conventional scans such as scans around a maximum of the beam size or scans with a controlled minimum spot size. This paper discusses the implementation issues of such a technique in the actual machine layou

    Autophagy processes are dependent on EGF receptor signaling

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    Autophagy is a not well-understood conserved mechanism activated during nutritional deprivation in order to maintain cellular homeostasis. In the present study, we investigated the correlations between autophagy, apoptosis and the MAPK pathways in melanoma cell lines. We demonstrated that during starvation the EGF receptor mediated signaling activates many proteins involved in the MAPK pathway. Our data also suggest a previously unidentified link between the EGFR and Beclin-1 in melanoma cell line. We demonstrated that, following starvation, EGFR binds and tyrosine-phosphorylates Beclin-1, suggesting that it may play a key inhibitory role in the early stage of starvation, possibly through the Beclin-1 sequestration. Furthermore, EGFR releases Beclin-1 and allows initiating steps of the autophagic process. Interestingly enough, when the EGFR pathway was blocked by anti-EGF antibodies, immunoprecipitated Beclin-1 did not bind the phospho-EGFR. In addition, an extended binding of p-Bcl2 either with Beclin-1 or with Bax was observed with a decreased activation of the stress-induced JNK kinase, thus avoiding the transduction pathways that activate autophagy and apoptosis, respectively. For this reason, we advance the hypothesis that the activation of the EGFR is a necessary event that allows the ignition and progression of the autophagic process, at least in melanoma cells
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