Parliamentary scrutiny as a function of interparliamentary cooperation among subnational parliaments

ABSTRACT The paper analyses the scrutiny activities of three different types of institutionalised form of interparliamentary cooperation with participation of subnational parliaments: the Conference of European Legislative Assemblies; the Baltic Sea Parliamentary Conference; and the Interregional Parliamentary Council of the Grande Région. For the purpose of analysis, the analytical parameters of parliamentary functions are modified and applied to the forms of institutionalised interparliamentary cooperation. It is shown that the exertion of scrutiny activities increases in relation to the age and institutionalisation of an interparliamentary cooperation. Ex ante control, which may consist of as little as demands, develops more easily than ex post control. Moreover, the exercise of the scrutiny function becomes more difficult when the level(s) that populate(s) the interparliamentary cooperation is/are not congruent with the level(s) that populate(s) the executive body of the respective international organisation. Interparliamentary cooperation of subnational parliaments struggles to scrutinise an organisation in which national executives play a major role.


Introduction
The Treaty of Lisbon expanded the scope of activity for parliamentary scrutiny of executive governance in the EU. Besides new provisions for parliamentary assemblies to control EU policy-making unilaterally, the Lisbon Treaty also introduced some new opportunity structures for interparliamentary cooperation (Art. 12 lit. f., TEU; Arts 9 and 10 Protocol No. 1, TEU). Since the entry into force of the Maastricht Treaty, specific kinds of interparliamentary cooperation have been a widely discussed topic in political science and practice (Benz, 2011;Crum & Fossum, 2009;Eppler, 2011Eppler, , 2015Fossum & Crum, 2012Maurer, 1996Maurer, , 2002Maurer, , 2009Maurer, , 2012. In particular, the introduction of rights for national parliaments to control legislative proposals of the EU Commission against the principles of subsidiarity and proportionality, and the dependency of parliamentary possibilities to obstruct and sanction the Commission's activity on participation quota, have been identified as catalysts that facilitate interparliamentary cooperation (Benz, 2011;Eppler, 2011). Other scholars consider the inclusion of national parliaments within the institutional fabric of EU governance to oscillate 'between despair and glimmers of hope' (Pollak & Slominski, 2013, p. 144). Interparliamentary cooperation might easily be conceived as an 'unfulfilled promise' (Raunio, 2009, pp. 8-13), especially if reduced to collective subsidiarity checks in the EU system (De Wilde, 2012;Mastenbroek et al., 2014;Raunio, 2010).
Against the background of the current state of research, this contribution analyses of INCOs in which subnational parliaments take part, and which are related to the EU. We apply the overall research questions of this special issue to INCOs: 'what kind of activities' INCOs 'deploy … related to the functions they take up', and 'how can we explain the varying … patterns of activity?' For the purpose of the analysis, we modify the analytical parameters of parliamentary functions, as used in the context of national parliaments (Marschall, 2005b;Patzelt, 2003), and apply the modified terms to INCOs. Leaving the representation function aside, as it has been widely discussed as a function of interparliamentary cooperation, we focus on the scrutiny function and develop two hypotheses deduced from historical and actor-centred neo-institutionalism and Putnam's approach to two-level games. Our hypotheses assume the exercise of scrutiny as a dependent variable of the age of an INCO, of the degree of its institutionalisation (Maurer, 1996;Scoffoni, 1992), and of the political levels that are linked through the parliaments acting in an INCO as well as through the executive institutions acting within the respective international organisation (Putnam, 1988). For the empirical analysis, we develop an original coding system and verify the hypotheses mainly through a comprehensive documentary analysis.

Research questions and case selection
The Lisbon Treaty strengthens interparliamentary cooperation both with regard to the European Parliament and the national parliaments (Art. 12 lit. f. TEU; Arts 9 and 10 Protocol No. 1, TEU). Although subnational parliaments are not explicitly mentioned with regard to their cooperation, they are for the first time explicitly referred to in the European treaties as a potential part of the system for subsidiarity control (Art. 6 Protocol No. 2,TEU). Note that all subnational parliaments with legislative powers are at least formally part of the 'early warning system' (Vara Arribas & Boudrin, 2011). The amplification of their networking activities has been analysed recently (Abels & Eppler, 2016).
Assuming that interparliamentary cooperationnetworkingis a crossdivisional function in which other parliamentary functions can be realised (Eppler, 2011), we argue that, like single parliaments, INCOs are 'multipurpose organisations' (Polsby, 1975). Consonantly to the introduction of this special issue, our first research question addresses the activities and their related parliamentary functions that INCOs take up. We thereby concentrate on their collective scrutiny function: to what extent, in which forms, and under what circumstances do institutionalised forms of interparliamentary cooperation with participation of subnational parliaments exercise scrutiny?
To assess and classify the scrutiny activities of INCOs with participation of subnational parliaments, CALREwhich claims to be the representation of subnational parliaments within the EU's systemis compared with other INCOs with participation of subnational parliaments related to more specific policies of the EU. An earlier study initiated by the European Centre for Parliamentary Research and Documentation of the European Parliament (ECPRD) and the Conference of the Speakers of National Parliaments notified 20 INCOs referring to the EU and integrating subnational parliaments (Maurer, 2004, p. 47). Some of these INCOs operate inside the EU, flanking organisations of cross-border cooperation; others work across its member states' borders, thereby linking subnational parliaments of EU members with such of non-EU members. These INCOs reflect the EU's efforts to enhance bilateral and multilateral, as well as cross-border cooperation between its member states, as well as its fostering of regional and macro-regional integration and its plurilateral trade, association and neighbourhood strategies.
To address our second research questionhow to explain varying patterns of scrutiny activities of institutionalised forms of interparliamentary cooperation with participation of subnational parliamentswe selected three cases: CALRE, the Baltic Sea Parliamentary Conference (BSPC) and the Interregional Parliamentary Council of the Grande Région (CPI-IPR). The differences between CALRE, CPI-IPR and BSPC regarding their 'targets', the number and profiles of their members, and their age enable us to test our hypotheses and explain varieties concerning their scrutiny activities. With CALRE, the BSPC and the CPI-IPR we focus on specific cases of transnational-multilateral corporative actors, which are composed of representatives from subnational parliaments and relate to the EU in general, or to a specific form of cooperation beyond or below. Conceptionally, we cover organisations that go beyond the classical definition of 'interparliamentary assemblies' (Kuper, 1991;Marschall, 2005a, p. 22), as we deal with subnational parliaments and include CALRE as conference of parliamentary speakers or presidents.

Theoretical framework
As with individual parliaments, research on parliamentary functions of INCOs allows us to categorise their work, their particular position in relation to other actors and institutions, and to capture change over a certain period of time: which functions lose in importance and which ones gain (Marschall, 2005b, pp. 133-196). Despite the difficulties of making a clear distinction between individual parliamentary functions (Loewenberg, 1971), which can be observed regarding the differences in nomenclature and details of catalogues of functions (Beyme, 1999;Marschall, 2005b, pp. 139-141;Patzelt, 2003, pp. 13-49;Raunio, 2011), it is possible to identify a core of functions which can be ascribed to parliaments of democratic systems (Maurer, 2002): representation/communication, legislation/policy-making, creation/ selection, and control/scrutiny. Prerequisite for a functional pattern that is applicable to INCOs is the consideration of the specific conditions of EU integration and/or of the (partly resulting) trans-or international sub-systems. Therefore, some 'classic' functions may not be detectable in the work of INCOs, such as the selective or legislative functions; others, such as representation and scrutiny, need to be framed by the institutional and procedural setup of the EU.
In national systems, parliamentary scrutiny (Kontrolle in German, or contrôle in French) relates to the possibility of the parliament controlling, checking, and constraining the governments' room for manoeuvre. Historically, in the course of the development of national parliamentarism and parliaments' emancipation from crown and government, parliamentary scrutiny occurred after the representation function. Today, the importance of scrutiny is still increasing due to transnationalisation and the globalisation of (inter)governmental agenda-setting and policy-making. However, in the vast majority of today's parliamentary democracies 'the classical separation of powers … has been replaced by a system of an interweaving of powers … ' (Schmuck & Wessels, 1989, pp. 287-288, translation by the authors). This is even more the case in the international context of INCOs, as traditional (national) parliamentary patterns of interaction and identification between political parties of the governmental majority and the opposition are not detectable in the international context of INCOs: owing to the lack of a clear delegation ratio (INCOs do not elect the executive body of the trans-, supra-or international organisation they refer to), there is no clearcut principal-agent relation between the INCO and the respective international organisation (Winzen, 2012).
However, the individual members of an INCOthe supranational, the national and the subnational parliamentsare able to sanction and rebuke their individual executive actors at home, i.e. in the national context where the delegation ratio defined above is effective. In his work on 'multi-level parliamentarism', Maurer (1996Maurer ( , 2002Maurer ( , 2009Maurer ( , 2012 argues in line with Kuper (1991) that 'interparliamentary synergies' (Maurer, 2009, p. 20, translation by the authors) may help to re-parliamentarise executive-dominated supranational decision-making if parliaments cooperate and share information to facilitate bilateral and multilateral scrutiny of their governments. Although the delegation ratio is not provided for at the trans-, supra-or international levels, INCOs are able to scrutinise the trans-, supra-or international organisation they refer to since the respective executive agents remain responsible vis-à-vis their parliaments on the supranational, the national, or the subnational level. For the post-Maastricht EU, Maurer observes increasing temporal correlation between the scrutiny activities of national parliaments and the European Parliament along the different stages of the policy cycle. His empirical data show that the 'synchronisation' can improve the scrutiny function if interparliamentary efforts to jointly scrutinise the executives are systematised and orchestrated at all stages of the policy cycle (Maurer, 1996). Building on these observations, we assume that an INCO is able to scrutinise the trans-, supra-or international organisation it refers to, as well as the respective national or subnational executives, if single members of the INCO are able and willing to share information and therefore likely to improve their ability to hold their executives to account on the national or subnational level. To check this assumption, we are particularly interested in interparliamentary scrutiny that is conducted directly by INCOs, and not of their individual units 'at home'. However, in contrast to the 'normative' (Herranz-Surrallés, 2014) approach of Crum and Fossum (2009) who focus on the representation function of interparliamentary cooperation, we rely on Maurer's rationalist argument, as it widens the perspective towards (joint) parliamentary (joint) scrutiny.

Development of hypothesis 1
In historical neo-institutionalist terms the evolution of institutionalised forms of interparliamentary cooperation is path dependent (Pierson, 2000(Pierson, , 2002. We assume that the functional scope of INCOs increases over time from pure representation and communication towards other, more specific functions, especially towards the scrutiny of their governmental counterparts (executive-dominated trans-, multi-or international organisations or cooperations). Therefore, INCOs take the same path as national parliaments in history and the European Parliament in the course of the widening and differentiation of the EU's material scope. Consequently, next to the basic function of representation and communication, the function of control or scrutiny evolves over time. The set-up of an INCO initiates the formation of experts and growing relations to other actorssuch as the delegating parliaments 'at home' and the international organisation the INCO is associated with. Coordination and feedback effects lead to solidification among all participating actors. This has an impact on the differentiation of the functional scope from pure representation, deliberation and communication to representation and scrutiny. Our first hypothesis is therefore: the longer an INCO exists, the more it exercises a scrutiny function vis-à-vis the (international or supranational) organisation it is associated with.
As we want to find explanations for the increasing scrutiny activities, we moreover assume that 'institutional stickiness' (Pierson, 2000(Pierson, , 2002 of INCOs evolvesthe ability to conduct the scrutiny function is dependent on the institutional strength of an INCO. 'Institutional strength' is expressed in the INCOs (developing) constitutional foundations, such as statutes, or procedural rules ('scope of control', Maurer, 2012, pp. 41-46). These fundamental documents frame scrutiny activities. First, they may address the challenge of parliamentary scrutiny to overcome the asymmetric distribution of information between the trans-, supra-, or international organisation and the INCO ('information imbalance ' Kevenhörster, 1984). Respective rules or routines would deal with the right of enquiry, the right to summon members of the government or the provisions on parliamentary questions. The common focus of these instruments is to collect and get hold of information as a precondition for further scrutiny activities. Second, these rules reflect the growing institutionalisation of an INCO which can be expressed in budgetary allocations, specific staff and secretariats, in the frequency of plenary sessions or in institutionalised committees. This kind of growing institutional density enables INCOs to evaluate information as a further precondition for effective scrutiny activities ('management of control', Maurer, 2012, pp. 41-46;Winzen, 2012, p. 660). Third, rules specify the forms and timing of ex ante and ex post scrutiny rights (see below, hypothesis 1b). Owing to their degree of institutionalisation, INCOs obtain a certain 'capacity' (Scharpf, 2000, p. 105) to act strategically and independently of the interests and agendas of other actors (Rittberger, 1995, pp. 102-117), especially of the trans-, supra-or international organisation it refers to, and therefore has an impact on the conduct of governments. Our hypothesis 1a is, therefore, that the more an INCO experiences institutionalisation, the more it exercises restraining scrutiny.
Due to the characteristics of the international sphere, only parts of the 'whole "arsenal" of different tools' (Saalfeld, 2000, p. 365) of the scrutiny function are relevant for INCOs. Immediate sanctions (Schnapp & Harfst, 2005) as well as mandate-based scrutiny strategies (Buzogány & Stuchlik, 2012) are rather unimportant. However, the different forms of scrutiny distinguished at the various stages of the ideal policy cycle are possible in interparliamentary cooperation: ex post scrutiny, with which events that have already taken place are checked in a reactive way (fr. contre-rôle); and ex ante scrutiny as a specific kind of proactive participation, expression of an opinion or demand at the earlier stages of a policy-making process (Marschall, 2005b, p. 169;Patzelt, 2003, pp. 31-34;Steffani, 1989). As within national parliamentary democracies, it is not always possible clearly to distinguish ex ante scrutiny activities from parliamentary participation in legislation (Helms, 2002, p. 25). However, specific input from INCO bodies towards the respective international organisation to draw on a specific piece of legislation is not understood as participation in legislation, since most INCOs have no right to (co-)legislate. In this paper, INCO demands to act are therefore classified as ex ante scrutiny. Within ex ante scrutiny, less responsiveness to other actors, particularly to the executive branches, and also less institutionalisation is necessary, as this kind of scrutiny covers all kinds of joint demands addressed towards those who enjoy decision-making authority. Regarding the exercise of ex post scrutiny, detailed information about the actions of the international organisation as well as institutional capacity to evaluate this information are necessary to enable INCOs to assess executive activity as well as to formulate an independent, content-related position. Therefore, our hypothesis 1b is that within institutionalised interparliamentary cooperation, ex ante scrutiny occurs more often than ex post scrutiny.

Development of hypothesis 2
Putnam considers the executive powers as a point of junction of two tactical 'games': the executives are the only linkage between the decision-making on the international level and the national system 'at home' which each has its own rules and institutional-procedural logics (Putnam, 1988). Owing to a lack of information on both levels, the executive powers are able to play off the two political levels against each other. One variation of these 'two-level games' is that governments, when acting in the international sphere, are able deliberately to diffuse, conceal or nebulise their responsibilities ('volunteer dilemma', Diekmann, 1985). For national or subnational parliaments, it might remain unclear who is responsible for international decisions. Consequently, these parliaments may not be able to fulfil their scrutiny function effectively vis-à-vis their own government's actions on the international level. Due to the 'asymmetry of information' (see above) between government and parliament, the national and subnational parliaments are at a disadvantage in a 'two-level game'.
If a trans-, supra-, or international cooperation or organisation is flanked by an INCO, its constitutive parliaments are additional boundary points between the national and the trans-, supra-, or international sphere. INCOs exercise scrutiny vis-à-vis a supranational, international or transnational organisation or cooperation in which the executive branch plays an important role (see above). Moreover, they build a pool to share information (as a prerequisite of scrutiny) between the national or subnational parliaments which is therefore a means to enable parliaments to scrutinise the activities of 'their' executive in supra-, trans-or international organisations. Obviously, this additional linkage between the national and the international system is only operational if executive and legislative powers bypass the same levels: if governments as well as parliaments are both junctions between the same levels. If an INCO is composed of subnational parliaments and associated with an international cooperation of subnational executives, two-level games can be controlled through coordinated, joint parliamentary scrutiny by the INCO. If the INCO parliaments originate from another level than the executives of the respective international cooperation, scrutiny activities are more difficult. This would be the case if an INCO that is composed of subnational parliaments was associated with an international cooperation of national executives that are not dependent on any level beyond the national one. Such a 'threelevel game' is then characterised by interaction frames in which no actor is able (in the case of parliaments) or willing (in the case of executives) to establish direct linkage between the international and the subnational levels. Not only is there a lack of possibilities of sanctions 'at home', we also expect that the missing scope of scrutiny at home has an impact on the scrutiny activities of the INCO. Our second hypothesis, therefore, is: the more congruence between the political level(s) of INCO's parliaments and the level(s) of the executives of the respective organisation exist, the more scrutiny activity takes place.

Empirical analysis
The three institutionalised forms of interparliamentary cooperation with participation of subnational parliaments analysed in this paper differ in their origin, founding idea and self-perception. The CALRE aims to strengthen subnational parliaments in EU matters on the national and European levels, to protect regional identities and to conduct networking as parliamentary and subnational actors in order to influence EU decisions. It corresponds therefore with the EU as a whole. The BSPC concentrates on a specific region only, namely the Baltic Sea region, and therefore exceeds the EU's border. It is the parliamentary counterpart of the Council of the Baltic States, in which the governments of the states and subnational regions bordering the Baltic Sea are represented. The BSPC was established in order to promote a common identity within the Baltic Sea region by closer cooperation between their national and regional parliaments. It dedicates itself exclusively to policies of the Baltic Sea region, originally starting with environmental issues and questions of maritime safety. The ultimate EU link originates from the Northern Dimension strategy and the related cohesion instruments of the EU. The CPI-IPR is the parliamentary assembly of the Grande Région and has emerged from the cross-border cooperation of SaarLorLux (cf. Art. 350 TFEU). The CPI-IPR is concerned with the economic, social and cultural position of the Grande Région, and relates to the cooperation of governments of the region, as well as to close cross-border cooperation of various other actors. In the longer term, the CPI-IPR aims to contribute to the development of deeper crossborder cooperation on policies that fall within the competence of its constitutive regions. These three institutionalised forms of cooperation vary in the quantity of represented parliaments and states, respectively subnational regions (however, bilateral or inner-state cooperations are not included), and with respect to the question of whether (a) only subnational parliaments take part, (b) subnational as well as national, or (c) national parliaments, the European Parliament and subnational parliaments participate.
In order to test our hypotheses, we have coded and analysed all documents adopted by plenary sessions of the INCOs under review. While CALRE and BSPR meet once per year, CPI-IPR normally meets twice. 1 While CALRE adopts one 'declaration' per meeting, the BSPR adopts one 'resolution' per meeting. The CPI-IPR adopts several documents per plenary meeting (up to seven in the reviewed period). In the case of CPI-IPR, particularly documents in the form of 'recommendations' are of interest: they are prepared by the committees of the CPI-IPR and adopted by the plenary. All in all, we dealt with 19 CALRE documents, 23 BSPC documents and 180 CPI-IPR documents, which we analysed through a self-developed coding scheme. 2 Additional information on the different interparliamentary cooperations was obtained through internet research and background talks.

Empirical analysis of hypothesis 1
Our first hypothesis is: the longer an INCO exists, the more it exercises a scrutiny function vis-à-vis the (international or supranational) organisation it is associated with.
The three INCOs under review were founded in different years (Table 1). The CPI-IPR, founded in 1986, is the oldest. The BSPC was founded in 1991, and CALRE, as the youngest INCO of this analysis, was founded in 1997.
The coding took all scrutiny activities into account that were adopted by the plenary sessions in any given year in their resolutions and declarations, irrespective of how often the plenary sessions take place or if there is one single document dealing with many control activities or many documents of which each is dealing with only one activity. The coding accounted for all kinds of joint demands to act towards the respective international cooperation or organisation (ex ante scrutiny, see above) as well as all kinds of content-related positioning on policy outcomes of the respective organisation (ex post scrutiny, see above).
The coded resolutions of the plenary meetings of the BSPC and the CPI-IPR show a significant increase of their scrutiny function over time. However, this is not the case with CALRE, whose scrutiny activities stay low over time (Figure 1).
In order to test hypothesis 1athe more an INCO experiences institutionalisation, the more it exercises restraining scrutinywe operationalised the levels of institutionalisation. As elaborated above, institutionalisation of an interparliamentary cooperation depends on its legal foundation. Rules may provide for information rights (as prerequisite for any kind of scrutiny) and for the procedural aspects of its right to conduct scrutiny. Institutional 'density' (the differentiation of work units and extent of committees, the (permanent) secretariat and its budget) may enable INCOs to evaluate information before starting scrutiny activities. While a path-dependent step-by-step institutional development and steady growth of the institutionalisation of INCO has been confirmed in background talks, detailed data of the institutional development over time have not been available. Therefore, we take the status quo of institutionalisation in January 2016 as a snapshot. As the control activities are dependent on the age of the interparliamentary cooperation, we take for each the average of their control activities in years 14-19 of their existence (Table 2). As expected under hypothesis 1a, we observe a relationship between the institutional extent and solidity of an INCO and its scrutiny activity. The three cases under review show an increasing gradient: CALRE, the interparliamentary cooperation with the lowest scrutiny activity, has standing rules of procedure. However, it is not equipped with an institutionalised secretariat or a specific budget. In addition, there is only one annual plenary session andapart from the working group on subsidiarity -CALRE is poorly equipped with some temporary working groups. Finally, CALRE's rules do not feature any specific scrutiny rights. The BSPC, by contrast, owns a secretariat and rules of procedure which contain rights for its own research and gaining its own information. Indeed, this parliamentary cooperation exerts more scrutiny. Apart from its rules of procedure, the CPI-IPR possesses a document which regulates the procedures concerning requests for answers from the executives, which is agreed between CPI-IPR and the executives of the Grande Région. It runs not only its own secretariat and budget but also six permanent committees, which are constitutionalised in the rules of procedure. The latter also contain various scrutiny instruments, which affect not only the executive bodies of the Grande Région but also its Economic and Social Committee and the single executives of the participating regions. CPI-IPR's rights extend from written requests over mutual presence in meetings to recommendations and statements, for which executives have to render an account to the parliamentary cooperation on how they plan to proceed with them. There is thus a potential for effective ex post scrutiny. In comparison with the other forms of interparliamentary cooperation, the CPI-IPR exerts scrutiny more comprehensively. Note: no BSPC was organised in 1993 (Kasack, 2005). Source: compiled by the authors. Regarding hypothesis 1bwithin institutionalised interparliamentary cooperation, ex ante scrutiny occurs more often than ex post scrutinythe three cases under review exert almost only ex ante scrutiny, rather than the more intricate ex post scrutiny. Although the CPI-IPR has the formal right to exert ex post scrutiny in its rules of procedure, we found almost no empirical evidence for its constant or systematic usage. As mentioned above, we took into account all kinds of joint demands to act towards the respective international cooperation or organisation (ex ante) as well as all kinds of content-related positions towards policy outcomes of the respective organisation or collaboration (ex post) (Table 3).
We found only one exception where ex ante scrutiny mixes with ex post scrutiny activity: in a CPI-IPR recommendation of 14 May 1990 the assembly referred to an existing bilateral agreement between Lorraine and the Saarland on transregional cooperation. Given that only parts of the agreement were implemented, the CPI-IPR explicitly referred to it (ex post) and called (ex ante) for the creation of a joint executive institution.
Regarding hypothesis 1, we found evidence for an increase of effective scrutiny exercise over time. The two related assumptions under hypotheses 1a and 1b have also been confirmed for the BSPC and the CPI-IPR. The number of scrutiny activities of CALRE has remained at a rather constant and low level over the years. Even if one takes into consideration that CALRE is the youngest INCO and the one with the smallest degree of institutionalisation, it remains unclear why the scrutiny function did not increase over time on a moderate level.

Empirical analysis of hypothesis 2
An explanation for the missing increase of CALRE's scrutiny function over time may be drawn from our second hypothesis: the more congruence between the political level(s) of INCO's parliaments and the level(s) of the executives of the respective organisation exist, the more scrutiny activity takes place.
The CPI-IPR relates to the Grande Région and therefore to an international organisation of executives which consists of deputies mainly from the subnational level (plus one national executive). The CPI-IPR itself is composed of representatives of the equivalent subnational parliaments (plus one national parliament). CPI-IPR thus features a complete overlap of deputising levels. The BSPC is the parliamentary body of the Council of the Baltic Sea States, which consists of national executives as well as the European Commission. The BSPC represents the parliaments of the two levels (national, EU), the subnational parliaments and some interparliamentary associations. As a result, there is a congruence of levels but additional actors interfere in the game ( Table 4).
The picture is different for CALRE. While CALRE consists only of representatives of subnational parliaments, it relates directly to the EU and therefore to an organisation that operates as a political, bicameral system sui generis. The latter is mainly linked to the national level (via the European Council and the Council), but features a directly elected, supranational parliament (the European Parliament). Therefore, 'two-level games' in the strict sense of Putnam take place mainly between the national and the EU levels. The main linkages between the levels are the national executives. The subnational parliaments represented in CALRE are not able to bridge the national and the EU levels and they have no possibility of holding national governments to account 'at home' (as they do not have a common 'home'). As assumed under hypothesis 2, the scrutiny activity depends on the congruence Table 3. Total numbers of ex ante and ex post scrutiny activities. 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 between levels. To illustrate our hypothesis, we take a snapshot of the situation in January 2016, referring to the congruence of levels and a crosssection of years 14-19 of the existence as a reference for the control activities (Table 5).

Conclusion
This paper has analysed three different INCOs with participation of subnational parliaments in the EU and thereby focused on their scrutiny function. The analytical parameters of parliamentary functions, as used in the context of national parliaments, have been modified and applied to institutionalised  forms of interparliamentary cooperation. The paper shows thatnext to the representation function which is conceived as a basic function of interparliamentary cooperationparliamentary scrutiny can indeed be exerted by INCOs and increases path-dependently over time. The density of interparliamentary cooperation grows with its age and affects the ability to conduct the scrutiny function. In addition, we found evidence for the argument that ex ante scrutiny develops more easily than ex post scrutiny. Moreover, we were able to show that the exercise of the scrutiny function becomes more difficult when the level(s) that compose(s) the interparliamentary cooperation is/ are not congruent with the level(s) that populate(s) the respective international organisation. The example of CALRE clearly shows that subnational parliaments struggle to scrutinise an organisation which is mainly composed of the national and supranational levels. The possibility of 'interparliamentary synergies' as analysed by Maurer (2002) in the context of interparliamentary cooperation between national parliaments and the European Parliament also has the potential to re-parliamentarise executive-dominated decision-making when subnational parliaments are involved. A closer analysis of policy impacts of scrutiny activities would therefore be an interesting step for further research.

Disclosure statement
No potential conflict of interest was reported by the authors.