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Against the Failures of Risk Regulation Liability and Safety in Air Traffic Management (ATM)

Published online by Cambridge University Press:  20 January 2017

Marta Simoncini  and
Giuseppe Contissa
Marta Simoncini
Affiliation:
University of Antwerp
Giuseppe Contissa
Affiliation:
European University Institute (EUI)
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Abstract

This article aims to analyse liability issues as a further means to regulate risks, in case the precautionary measures of the delivered safety system fail. Through liability, the risk that cannot be prevented can be transferred onto those parties who are in the best position to spread them. The allocation of liability thus works as an incentive to the correct functioning of the preventive measures. Liability rules appear to be a key legal remedy which can ensure both tort reparation and a fair and efficient distribution of burdens in a legal order. In this vein, air traffic management (ATM) is addressed as a case study, which shows the main issues and the gaps that liability rules face when dealing with the trade off between risk and safety as conveyed by technology.

After having clarified the nature of the relations between risk and liability on the one hand, and automation and liability on the other hand, this article analyses liability issues in the framework of ATM by approaching this topic in a comparative way between the National Airspace System (NAS) of the United States of America (USA) and the Single European Sky (SES) of the European Union (EU).

Type
Transnational Risks and Multilevel Regulation: A Cross–Comparative Perspective
Information
European Journal of Risk Regulation , Volume 4 , Issue 2 , June 2013 , pp. 175 - 189
Copyright
Copyright © Cambridge University Press 2013

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References

1 Bovens, Mark A. P., The quest for responsibility: Accountability and citizenship in complex organisations (Cambridge: Cambridge Univ Press, 1998).Google Scholar

2 The model of accident causation is the so called the Swiss cheese model, according to which the typical accident occurs because several errors have occurred at all levels in the organisational chain in a way that made such accident unavoidable. The causation chain therefore originates due to the alignment of all the necessary “windows of opportunity” (the holes of the cheese) at all levels in the organisation, thus leading to the occurrence of a particular accident. In the literature see Reason, James, Human error (Cambridge: Cambridge University Press, 1992).Google ScholarPubMed

3 See Bennett, Simon, “The 1st July 2002 mid-air collision over überlingen, Germany: a holistic analysis”, 6 Risk Management (2004), pp. 31–49.Google Scholar

4 See in particular Leloudas, George, Risk and Liability in Air Law (London: Maritime & Transport, 2009);Google Scholar

5 Emery, Fred E. and Trist, Eric, “Socio–technical systems”, In Charles West Churchman and Michel Verhulst (eds.), Management Sciences: Models and Techniques,Vol. 2 (London: Pergamon Press, 1960), pp. 31 et sqq.Google Scholar; Mumford, Enid, “The Story of Socio-Technical Design: Reflections on its Successes, Failures and Potential”, 16:4 Information Systems Journal (2006), pp. 317 et sqq. CrossRefGoogle Scholar; Ottens, Maarten, Franssen, Maarten, Kroes, Peter, and van de Poel, Ibo, “Modelling infrastructures as socio-technical systems”, 2(2) International Journal of Critical Infrastructures, (2006), pp. 133 et sqq. CrossRefGoogle Scholar; Baxter, Gordon and Sommerville, Ian, “Socio–technical systems: From design methods to systems engineering”, 23(1) Interacting with Computers (2011), pp. 4 et sqq. CrossRefGoogle Scholar

6 Among the existing production, see Jones, Trevor O. and Hunziker, Janet (eds.), Product liability and innovation: managing risk in an uncertain environment(Washington DC: The National Academies Press, 1994).Google Scholar

7 Among the existing production, see Reason, James, Managing the Risks of Organisational Accidents (Aldershot: Ashgate, 1997)Google Scholar; Perrow, Charles, Normal Accidents: Living With High Risk Technologies, (Princetown: Princeton University Press, 1984)Google Scholar; Hollnagel, Erik and Woods, David D., Joint cognitive systems: Foundations of cognitive systems engineering, (Boca Raton: CRC Press, 2005);CrossRefGoogle Scholar Kantowitz, Barry and Sorkin, Robert, “Allocation of Functions”, in Salvendy, Gavriel (ed.), Handbook of human factors, (New York:Wiley, 1987), pp. 356 et sqq.Google Scholar

8 In the literature, among others see Beck, Ulrich, Risk Society: Towards a New Modernity (New Delhi: Sage, 1992)Google Scholar; Giddens, Anthony , Consequences of Modernity (Cambridge: Polity Press, 1990)Google Scholar; Giddens, Anthony, “Risk and Responsibility”, 62 Modern Law Review (1999), pp. 1 et seqq.CrossRefGoogle Scholar

9 With the aim of reducing the impact of major losses, beyond the probability analysis, regulation should consider the severity of the threat for human health, the degree of reversibility of its effects, the possibility of delayed consequences and the perception of the threat based on available scientific data; in this regard, see Sunstein, Cass R., “Irreversible and Catastrophic”, 91 Cornell Law Review (2005–2006), pp. 841 et seqq., at pp. 893–894Google Scholar

10 Calabresi, Guido, The Cost of Accidents. A Legal and Economic Analysis (New York: Yale University Press, 1970)Google Scholar; Rose-Ackerman, Susan, “Product Safety Regulation and the Law of Torts”, in Hunziker, Janet R. and Jones, Trevor O. (eds.), Product Liability and Innovation. Managing Risk in an Uncertain Environment (Washington D.C.: National Academy Press, 1994), pp. 151 et seqq., at pp. 153 et seqq.Google Scholar; Brüggemeier, Gert (2004), Common Principles of Tort Law. A Pre-Statement of Law, (London: BIICL, 2004), at pp. 3 and 22.Google Scholar

11 Coase, Ronald, “The Problem of Social Cost”, 3 Journal of Law & Economics 1960, pp. 1 et seqq.CrossRefGoogle Scholar; Calabresi, Guido, The Cost of Accidents, cit.; Steven Shavell, Economic Analysis of Accident Law (Cambridge, Mass.: Harvard University Press, 1987) at 5 et seqq.Google Scholar; Shavell, Steven, “Liability for Harm versus Regulation of Safety”, in Wittman, Donald A. (ed.), Economic Analysis of the Law. Selected Readings(Malden, Mass.: Blackwell, 2003), at 59 et sqq Google Scholar; Brown, John P., “Economic Theory of Liability Rules”, in Wittman, Donald A. (ed.), Economic Analysis of the Law. Selected Readings, cit., at 34 et sqq; Steven Shavell, Foundation of Economic Analysis of Law (Cambridge, Mass.: Harvard University Press, 2004), at 177 et sqq.Google Scholar; Mitchell Polinsky, A. and Shavell, Steven, Handbook of Law and Economics (North Holland: Elsevier B.V., 2007), at 142 et sqq.Google Scholar

12 On the different consequences of different liability systems see Guido Calabresi, “First Party, Third Party, and Product Liability Systems: Can Economic Analysis of Law Tell Us Anything About Them?”, 69 Iowa Law Review (1984), pp. 833 sqq., at 834 et sqq.

13 Get Brüggemeier, Common Principles of Tort Law. A Pre-Statement of Law, cit., at p. 111.

14 This is the case of Italy, where the state has been held liable for omitted vigilance on blood products and transfusions with regard to the transmission of infections on the basis of a causal link, only since the time when the infection risks were known to medical science; see Supreme Court of Cassazione, III, civ., 31 May 2005, n. 11609. But note that this decision has been challenged by the following case law of lower courts, on the basis of the necessity to compensate the damage to psycho-physical integrity, coming also from unforeseeable risks, since due care is related to the correct development of safety controls before the blood transfusion (regardless of the specific virus in question). See Tribunale di Roma, II, civ., 3 January 2007.

15 This is a “technology-forcing standard” model, which introduces obligations suitable to pursue technology innovations that can affect the functioning of the market itself. Interesting is the American case Union Electric Co. v EPA, 427 U.S. 246 (1976), where the Supreme Court held that in the implementation of the State Implementation Plans (SIP) concerning air quality and implementing federal standards, the operators could not object the economic and technological feasibility in the achievement of the emissions’ expected levels. In the literature see Breyer, Steven, Regulation and Its Reform (Cambridge, Mass.: Harvard University Press, 1982), at pp. 106–107.Google ScholarPubMed It is not by chance that European regulation has mitigated the potential impact of this model on competition rules by taking care of the economic impact of technology-forcing standards. For an example, see art. 2, n. 12, lett. b), of the directive 2008/1/EC on the quality of air, which associates the best available techniques with the costs and the benefits of their application.

16 See Supreme Court of Cassazione, III, civ., 29 January 2013, n. 1871.

17 Leloudas, George, Risk and Liability in Air Law, cit., at pp. 29–31.Google Scholar

18 Gert Brüggemeier, Common Principles of Tort Law. A Pre-Statement of Law, cit., at p. 117.

19 Brüggemeier, Gert, Modernising Civil Liability Law in Europe, China, Brazil and Russia (London: Cambridge University Press, 2011), at p. 101CrossRefGoogle Scholar; Gert Brüggemeier, Common Principles of Tort Law. A Pre-Statement of Law, cit., at p. 159.

20 Among others, see the already cited case of the mid-air collision of two civil aircraft over überlingen in 2002 and the accident occurred at the Linate aerdrome in 2001 due to runway incursion, which is one of the most serious crash on the ground. It should be noted that in this last case the latent conditions and organisational problems that contributed – besides crucial human errors – to the occurrence of this accident on the ground could not be completely pinpointed by the Italian courts, because of the complexity of the legal framework concerning the allocation of competencies between the Italian civil aviation agencies. See the judgment of the Italian Supreme Court of Cassazione, IV, pen., 19 February 2008, n. 22614.

21 This liability model can be framed in the French concept of responsabilité sans faute, which pursues the solidarity principle in the allocation of risks. See Rivero, Jean, Droit administratif (Paris: Dalloz, 1975) at p. 279 Google Scholar; Moreau, Jacques, La responsabilité administrative (Paris: PUF, 1996) at p. 99 Google Scholar; Lazari, Antonio, Modelli e paradigmi della responsabilità dello Stato (Torino: Giappichelli, 2005) at pp. 149–151.Google Scholar Note that the strict liability regime has been implemented also in Spain (see art. 139 (2) of Ley de Régimen Juridico de las Administracionés Públicas y del Procedimento Administrativo Común, of 26 November 1992) as a means of protection against public action, regardless of the qualification of the conduct and the damage (responsabilidad objectiva global), but its extent has been reduced progressively. See Puigpelat, Oriol Mir, La responsabilidad patrimonial de la administración hacia un nuevo sistema (Madrid: Civitas, 2002)Google Scholar. The roots of strict liability can also be found in German law, even if in this case the premise of compensation is not the solidarity principle, but the liberal claim to restore individual proprietary rights (intended not only as property rights, but also as rights to life and health, according to the German Constitutional Court's case law. See BVerfG of 14 July 1981, Pflichtexemplar–Entscheidung, and of 15 July 1981, Naßauskiesung–Beschluß) affected in their very heart: since the achievement of public goals imposes a special sacrifice on the proprietary rights of specific parties, compensation should be provided in order to keep on protecting these fundamental rights of individuals. See Badura, Peter, “Fondamenti e sistema della responsabilità dello Stato e del risarcimento pubblico nella Repubblica federale di Germania”, Rivista trimestrale di diritto pubblico (1988), pp. 399 et seqq., at pp. 400 and 404–406.Google Scholar

22 In order to make this liability regime tenable, this is generally mitigated by the introduction of caps to the extent of damage to be compensated. Actually, the principle of full compensation of damages can also be limited upon the consideration of the injured person’s contribution to the occurrence of the damage (contributory negligence, comparative fault and causation) which are related to the assumption of risk and the duty to mitigate the possible damage.

23 See the Convention for the Unification of Certain Rules for International Carriage by Air, 1999 (so called Montreal Convention); the Convention on Damage Caused by Foreign Aircraft to Third Parties on the Surface, 1952 (so called Rome Convention).

24 National laws and interstate agreements can allocate the primary liability for failures in the provision of ANS to the State in whose territory the damage occurred – irrespective of the effective service provider (territorial State doctrine); or to the State providing the ATS (provider State doctrine); or to the effective foreign service provider, charged before the delegating State (effective service provider doctrine).

25 According to the ICAO definition (Circular 328 / AN 190) an Unmanned Aircraft (UA) is “an aircraft which is intended to operate with no pilot on board”. By extension, an Unmanned Aircraft System is the combination of an UA and the associated elements enabling its flight, such as Pilot Station, Communication Link and Launch and Recovery elements. There may be multiple UAS, Pilot Stations or Launch and recovery Elements within a UAS. There are two classes of UAS: Autonomous Unmanned Aircraft Systems (AUAS) and Remotely Piloted Aircraft Systems (RPAS). The ICAO regulatory framework focuses on RPAS, as the only UAS that will be able to be integrated into the international civil aviation system in the foreseeable future.

26 Zollers, Frances E., McMullin, Andrew, Hurd, Sandra, and Shears, Peter, “No more soft landings for software: Liability for defects in an industry that has come of age”, 21 Santa Clara Computer and High Technology Law Journal, (2004), pp. 745 et sqq. Google Scholar

27 Of particular interest in this context are the “aeronautical charts” cases (Aetna Casualty & Surety Co. v. Jeppesen & Co., 642 F.2d 339, 342–43 (9th Cir.1981); Saloomey v. Jeppesen & Co., 707 F.2d 671, 676–77 (2d Cir.1983); Brocklesby v. United States, 767 F.2d 1288, 439 (9th Cir.1985); Fluor Corp. v. Jeppesen & Co., 170 Cal.App.3d 468, 475, 216 Cal.Rptr. 68, 71 (1985)), where the courts have routinely held that the charts are products for purposes of product liability and that strict liability can be applied. In these cases, the courts categorized information (provided in a chart, or by analogy in a software system) as a product, assuming that a nautical chart or an airline chart is similar to other instruments of navigation such as a compass or radar finder which, when defective, can prove to be dangerous. This provides at the same time the best analogy to software and the fullest analysis and supporting arguments for why software should be subjected to strict liability.

28 Hollnagel, Erik and Woods, David D., Joint cognitive systems: Foundations of cognitive systems engineering (Boca Raton, FL: CRC Press, 2005).CrossRefGoogle Scholar

29 Perrow, Charles, Normal accidents: Living with high-risk technologies (New York: Basic Books, 1984).Google Scholar

30 Teubner, Gunther, “Rights of Non-humans? Electronic Agents and Animals as New Actors in Politics and Law”, 33 Journal of Law and Society (2006), pp. 497 et sqq. CrossRefGoogle Scholar

31 Federal Aviation Act, P.L. 85-726, 72 Stat. 731. Approved on 23 August 1958.

32 The Code of Federal Regulations is the codification of the general and permanent rules published by the executive departments and agencies of the United States Government. The regulations are divided into 50 different codes, called Titles, that represent broad areas subject to Federal regulation.

33 FAA Order 8000.369, “Safety Management System Guidance”, of 30 September 2008.

34 FAA, “What Is NextGen?”, 2011, available on the Internet at: <http://www.faa.gov/nextgen/why_nextgen_matters/what/> (last accessed on 22 April 2013).

35 The main goals of NextGen are to 1) reduce flight delays by improving airport operations; 2) improve aviation's impact on the environment through reduced CO2 emissions and fuel use; and 3) make the airspace safer via more precise tracking, improved information- sharing, and implementing a Safety Management System. Plans for NextGen were developed through an inter-agency Joint Planning and Development Office (JPDO), whose members include the FAA, the National Aeronautics and Space Administration (NASA), the Departments of Transportation, Homeland Security, Defense, and Commerce, and the White House Office of Science and Technology Policy.

36 See FAA, “Destination2025”, 2011, available on the Internet at: <http://www.faa.gov/about/plans_reports/media/Destination2025. pdf> (last accessed on 22 April 2013).

37 H.R. 658: FAA Modernization and Reform Act of 2012.

38 Ibid., Title II.

39 Ibid.,Title II, Subtitle B.

40 Ibid.,Sections 312 and 313.

41 in 1999, in Abdullah v.American Airlines Inc. (Abdullah v. American Airlines, Inc., 181 F.3d 363, 367 (3d Cir. 1999)), the U.S. Court of Appeals for the Third Circuit held that plaintiffs’ common law claims of negligence and recklessness were preempted because the Federal Aviation Act and the regulations promulgated under the act occupied the “entire field of aviation safety.” The court reasoned that preemption does not flow from the wording of any specific regulation, but is derived from “the overall concept that aircraft may not be operated in a careless or reckless manner.” The court concluded, “that because of the need for one consistent means of regulating aviation safety, the standard applied in determining if there has been careless or reckless operation of an aircraft, should be federal; state or territorial regulation is preempted.”

42 More precisely, according to the “field preemption” argument, any determination of whether a product is unsafe or defective must be based solely on FAA standards for design and certification of the aircraft, because such a comprehensive and pervasive scheme of federal regulation would prove that Congress intended to preempt the entire field of aviation from state regulation. Instead, according to the “conflict preemption” argument, state law is preempted when it actually conflicts with federal law. Since FAA has promulgated extensive safety standards and regulations relating to their products, any state law requirements for additional safety measures would necessarily present a conflict, and therefore would be preempted.

43 Wyeth v. Levine,129 S.Ct. 1187, 1199–2000 (2009).

44 Er, et al. v.Boeing, Circuit Court of Cook County, Ill., Slip opinion, case No. 2009 L 013791 (Judge Dennis J. Burke) (Cir. Ct. Cook County, Aug. 18, 2010).

45 28 U.S.C.A. § 1332.

46 28 U.S.C.A. § 1441(c)

47 28 U.S.C. §§1346(b), 2671 et sqq.,

48 Art.2 reg. 1070/2009, introducing Art.9a to the Reg 550/2004.

49 See art.11 reg. 1070/2009 and reg. 691/2010.

50 See art. 1 of the Regulation (EC) No 1108/2009 of the European Parliament and the Council of 21 October 2009 amending Regulation (EC) No 216/2008 in the field of aerodromes, air traffic management and air navigation services and repealing Directive 2006/23/EC.

51 See art. 5 reg. 216/2008 and Commission Regulation (EC) No 748/2012 of 3 August 2012 laying down implementing rules for the airworthiness and environmental certification of aircraft and related products, parts and appliances, as well as for the certification of design and production organisations. In particular, Regulation (EC) No 1592/2002 establishing EASA attributed to this agency the responsibility for the airworthiness and environmental compatibility of aeronautical products, but it was clearly understood that optimum and uniform safety standards and the establishment of fair competition for air operators could only be achieved by extending the scope of the text to include air operations (OPS) and flight crew licensing (FCL). On this ground, the tasks of the Agency has be extended to include air operations, pilots’ licences and, within the limits set by the Chicago Convention, the safety of third-country aircraft. See art. 7 and art. 21 reg. 216/2008 and on OPS see Commission regulation (EU) 965/2012 of 5 October 2012 laying down technical requirements and administrative procedures related to air operations pursuant to Regulation (EC) No 216/2008 of the European Parliament and of the Council; on FCL see Commission regulation (EU) No 290/2012 of 30 March 2012 amending Regulation (EU) No 1178/2011 laying down technical requirements and administrative procedures related to civil aviation aircrew pursuant to Regulation (EC) No 216/2008 of the European Parliament and of the Council.

52 See recital 1 of the Reg. (EC) 1108/2009.

53 This is the so called European Aviation Safety Programme (EASP) which is based on a strategy which set the goals and policies, a programme which provides the regulations and activities aimed at improving safety and a plan which concerns the safety assessment and the related actions.

54 See 21.A.3B reg. 748/2012 on initial airworthiness, which focuses on safety management in the area of design and manufacture; and Part-M, Part-145 and Part-147 of Commission Regulation (EC) No 2042/2003 of 20 Novemebr 2003 on continuing airworthiness, which concerns safety management in the area of maintenance, management and maintenance training organisations.

55 Art. 19 of the Reg. (EC) No 216/2008 of the European Parliament and the Council of 20 February 2008 on common rules in the field of civil aviation and establishing a European Aviation Safety Agency, and repealing Council Directive 91/670/EEC, Regulation (EC) No 1592/2002 and Directive 2004/36/EC.

56 See recital 12 of the Regulation (EC) No 1108/2009 and Communication from the Commission to the Council, the European Parliament, the European Economic and Social Committee, and the Committee of the Regions COM (2005) 578 of 15 November 2005, Extending the tasks of the European Aviation Safety Agency. An agenda for 2010, § 1.2

57 Commission Regulation (EC) No 736/2006

58 See regulation (EU) No 996/2010 of 20 October 2010 of the European Parliament and of the Council on the investigation and prevention of accidents and incidents in civil aviation and repealing Directive 94/56/EC.

59 Meroni doctrine originates from the joint cases 9/56 and 10/56, Meroni & c. spa v. ECSC High Authority [1958], ECR 1957–1958, and it has been implemented by the case 98/80, Romano [1981], ECR 1981. Today a debate is ongoing on the opportunity of maintaining this constitutional framework, especially in the light of the new feature provided for European administrations by the Lisbon Treaty (art. 298 TFEU). In the literature see, among others, Griller, S. and Orator, A., “Everything under control? The “way forward” for European agencies in the footsteps of the Meroni doctrine”, in 35 European Law Review (2010), pp. 3 et seq.Google Scholar; Majone, Giandomenico, “Foundations of Risk Regulation: Science, Decision–Making, Policy Learning and Institutional Reform”, in 1(1) European Journal of Risk Regulation (2010), pp. 16–18; id.Google Scholar, Dilemmas of European Integration (Oxford: Oxford University Press, 2005), pp. 124–142 Google Scholar; Sorace, G., “Una nuova base costituzionale europea per la pubblica amministrazione”, in Chiti, Mario P. and Natalini, Alessandro (eds.), Lo spazio amministrativo europeo. Le pubbliche amministrazioni dopo il trattato di Lisbona (Bologna: Il Mulino, 2012), pp. 45 et sqq., at pp. 55 et sqq.Google Scholar

60 In this regard, see Fisher, Elizabeth, Risk Regulation and Administrative Constitutionalism (Oxford: Hart Publishing, 2007), at pp. 28–34.Google ScholarPubMed

61 It can however be imagined that even if the main responsibility for achieving the European standards should be allocated on States, it would possible to allocate on EASA a specific liability for faulty supervision when States do not comply with the requested rules. On the contrary, EASA has specific executive powers which seem to be compatible with the principle of institutional balance within the EU, such as in the case of the type certification of products, the approval of design organisations, and the approval of ATM/ANS providers with a pan-European nature.

62 See the Federal Aviation Act 1958.

63 In order to compel the persons and the undertakings to comply with EU regulations and its implementing rules, both the EU Commission at the request of EASA and the Member States can impose fines and penalties, which should be effective, proportionate and dissuasive. See art. 25 and 68, reg. 216/2008.

64 See Council Regulation 2027/97/EC on air carrier liability in the event of accidents and the following amending Reg.889/2002/ EC, which transposes the Montreal Convention in the European legal order. In this last case, it is also important to underline that the EU itself signed the Montreal Convention indicating its intention to become a party to the agreement by ratifying it; see recital 5 of reg. 889/2002.

65 On this aspect, it is relevant the research currently carried out by the ALIAS (Addressing Liability Impact of Automated Systems, www. aliasnetwork.eu) project, co-financed by EUROCONTROL on behalf of the SESAR Joint Undertaking as part of Work Package E: the main outcome expected is the development of the “Legal Case”, that is a methodological tool to systematically identify and address the liability issues of automated ATM systems, including recommendations and guidelines to ensure that relevant legal aspects are taken into consideration at the right stage of the design, development and deployment process. The Legal Case is being built on the same line of the other “Cases” developed or under development within the SESAR Programme (e.g. the Safety Case, the Environment Case, the Human Factors Case, etc.).

66 In fact, risks can be reduced only through appropriate regulative choices, in combination with a “just culture” of safety. According to such concept, operators shall be encouraged, and even rewarded, for providing essential safety–related information, while a clear line shall be drawn that differentiates between acceptable and unacceptable behavior. In particular, it is argued that the working of the judicial system (in particular the criminal enforcement) may often have a negative impact on safety, since to increase safety and in particular to favour reporting and collaboration, it is needed that front line operators and others are not punished for actions, omissions or decisions taken by them that are commensurate with their experience and training, while gross negligence, wilfull violations and destructive acts shall not be tolerated. Marta Simoncini is an FWO post-doctoral research fellow at the University of Antwerp; Giuseppe Contissa is a research assistant at the European University Institute (EUI). This article is the result of a common reflection by the Authors. Marta Simoncini wrote sections 2 and 4.2; Giuseppe Contissa wrote section 3 and 4.1. The Authors want to thank the anomymous referees for their comments. Usual disclaimer applies.