The paper is extremely thinly researched in an area that is generating a significant amount of scholarly commentary and, as such, it is rather disappointing because the authors seem to be (re)discovering powder by emphasising the interaction between procurement and competition law rules. However, some of the main points the authors make in relation to the pre-existing case law of the CJEU are worth considering.
Firstly, they stress the practical complications that the open-ended definition of concession creates, particularly in terms of the difficulty of assessing when the transfer of risks to the concessionaire suffices to be covered by Directive 2014/23 instead of Directive 2014/24 or Directive 2014/25 [for discussion, see C Risvig Hansen, Contracts not covered or not fully covered by the Public Sector Directive (Copenhagen, DJOF, 2012)76-102; A Sanchez-Graells, 'What Need and Logic for a New Directive on Concessions, Particularly Regarding the Issue of their Economic Balance?' (2012) 2 European Public Private Partnership Law Review 94-104; and R Craven, 'The EU's 2014 Concessions Directive’ (2014) 23 Public Procurement Law Review 188-200].
Secondly, they explore the applicability of Art 101 TFEU to bidders that opt to team up or bid jointly for concession contracts. Their remarks are interesting and topical, as the recent publication of the 'Consortium Bidding' guidelines by the Irish Competition and Consumer Protection Commission evidences. I found their warning on the need to limit the exchanges of information between consortium partners particularly relevant (pp. 19-20), as joint participation in selected procurement projects could be the conduit for cartelising behaviour and this is an issue that requires careful consideration.
On this point, it is interesting to see how Farley and Pourbaix stress that utilities concessions may trigger the application of competition law because, almost by definition, the contracting entity will be engaged in 'downstream' economic activities. Their discussion of the Luton Airport case is certainly informative [Arriva the Shires Ltd v London Luton Airport Operations Ltd  EWHC 64 (Ch)].
This may be a point to take into consideration in the future to (possibly) limit the FENIN-SELEX exemption in case contracting authorities outside the utilities sector engage in (partial) downstream economic activity, which is likely to be the case of some in-house or public-public cooperation arrangements, which can now offer up to 20% of their supplies or services in the 'private market' under the rules of Directive 2014/24. This would be particularly easy on the basis of the 'severability' of activities for the purposes of competition law [Aéroports de Paris v Commission, C‑82/01, EU:C:2002:617], which in my view would be a most welcome development of this area of the law.
Finally, Farley and Pourbaix focus on specific competition law aspects of the new EU Concessions Directive. Of the issues they mention (other than the duration of the concession contract), the most interesting are the possibility to exclude infringers of competition law (on which see the recent case law of the CJEU here), and the interaction between State aid rules and the modification of concession contracts [for discussion, see A Sanchez-Graells, 'Public Procurement and State Aid: Reopening the Debate?' (2012) 21(6) Public Procurement Law Review 205-212].
On the issue of exclusion, the paper stresses burden of proof difficulties and advocates for a careful enforcement of the power to exclude undertakings suspected of competition violations, and points (without mentioning) at corporate human rights such as the presumption of innocence, which would have deserved more detailed consideration [for general discussion, see A Sanchez-Graells and F Marcos, '"Human Rights" Protection for Corporate Antitrust Defendants: Are We Not Going Overboard?'
(2014) University of Leicester School of Law Research Paper
On the issue of State aid being (implicitly) granted as a result of a modification of a contract during its term, the paper emphasises that the increased flexibility in the choice of procedures and the possibility to modify the contract (potentially without value limit, despite the stress on 50% that Farley and Pourbaix wrongly put in p. 24-25) in a relatively generous array of cases restricts the 'Altmark' presumption and requires a substantive assessment of the conditions of the contract [something already advocated for in A Sanchez-Graells, Public procurement and the EU competition rules (Oxford, Hart, 2011) 118-121 and, in more detail, in ibid, 'The Commission’s Modernization Agenda for Procurement and SGEI', in E Szyszczak & J van de Gronden (eds) Financing SGEIs: State Aid. Reform and Modernisation, Legal Issues of Services of General Interest Series (The Hague, TMC Asser Press / Springer, 2012) 161-181].
A point of contention, though, refers to the treatment of concession contracts as conduits for State aid. Farley and Pourbaix consider that:
Contracting Authorities may be able to take a certain amount of comfort from the fact that many concessions may not qualify as State aid in any event, on the basis that the remuneration was not granted through State resources. This will at least be the case in those situations where the concessionaire is remunerated entirely by third parties. Following the CJEU’s ruling in PreussenElektra [PreussenElektra, C-379/98, ECLI:EU:C:2001:160] this will still be the case even if the State sets the price that third parties need to pay for the relevant goods or services. (P. 24).
Even if they indicate that mixed arrangements which include some sort of subsidy could erode this possibility to duck State aid rules, I think that they present the situation in a way that excessively narrows down their application. Indeed, on that point, it may worth stressing that the CJEU has relatively recently adopted a less formalistic approach and considered that certain aspects of public control over third party revenue (which are common to concession contracts) may trigger the dis-application of the PreussenElektra exception (see comment here).
In particular, in Vent De Colère and Others, C-262/12, EU:C:2013:851, the CJEU found that:
Hence, even decisions concerning authorizations to raise user fees (without offering any additional public support or implying any extension of the length of the concession) may trigger State aid application, which is a case most concession contracts usually contemplate. Hence, the interaction between the prohibition of State aid in Art 107(1) TFEU and the rules on modification of concession contracts in Directive 2014/23 is more intense than Farley and Pourbaix's paper presents.
Article 107(1) TFEU must be interpreted as meaning that a mechanism for offsetting in full the additional costs imposed on undertakings [...] that is financed by all final consumers [...] constitutes an intervention through State resources (C-262/12, para 37).
Overall, then, the paper is not groundbreaking and, if the existing literature had been researched, it would probably have been of a higher academic interest (as it is published, though, it certainly is oriented to practitioners) and could possibly have reached a deeper level of analysis. In any case, given the novelty of Directive 2014/23, Farley and Pourbaix's paper can certainly raise awareness of the important issues they mention.