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Károly GERGELY: Forgotten Differentiation

An Inquiry into the Informal Differentiated Integration


The concept of differentiated integration (DI) has a history of over 70 years and since its appearance in the 1950s, an immense number of definitions attempted to pinpoint what exactly this expression refers to.[1] In the case of DI, even though definitions are countless (one study enumerated at least 30 conceptual models of DI)[2], the majority of academic literature has agreed on broadly defining it as ‘as the territorial variation of validity of EU legal rules within and beyond the EU member states.’[3] This legal focus of the academic literature also resulted in a nearly exclusive focus dedicated to the formal and legal aspects of DI, thus the field became increasingly dominated by institutional arguments and by the ‘institutionalist literature.[4]

The definition one ascribes to a concept inevitably defines the kind of evidence used in addressing problematics arising around said concept. The body of evidence used by the vast majority of scholars discussing DI is therefore a mixture of Founding Treaties and other legal texts. Understanding differentiated integration ‘in a much wider context’, this essay aims to shed light on the ‘uncharted depth of projects’ of DI and to bring forth formerly disregarded evidence.[5]

This essay proposes to interrogate this ‘uncharted depth’ through two main sections. The first section looks at the accession process of the 2004 enlargement and argues that the transposition of the acquis communautaire did not lead to uniformity between Member States, rather, it created a hidden layer of differentiation. The second section argues that this ‘hidden’ differentiation had important ramifications for the development of the new members, as the lack of changes ‘locked in’ in certain cases, therefore cementing the gap between old and new member states. The essay’s argument, put forward in these two parts makes the case for moving beyond the institutional-legal narrative of differentiated integration and argues for a more serious scholarly analysis of the informal arrangements that define and shape the EU.

Introducing a Forgotten Aspect

The typologies of various DI structures are just as numerous as the names for DI or the definitions given to pinpoint the exact nature of this phenomenon, resulting in an ‘excess of terminology which can give even the most experienced specialist of European integration a severe case of semantic indigestion.’[6] This essay, therefore, does not aspire to enter the intellectual battlefield of typologizing, an intellectual endeavour which Peter Baldwin likened to the ‘works of bean-counters and bookkeepers.’[7] Nevertheless, a look at the variety of typologies of DI structures is indicative of the nature of the evidence most DI scholars utilize in their works. If one examines the corpus of academic texts, the almost exclusive reliance on EU treaties and other legal texts in order to determine the level of integration is staggering. This indicates a level of naïveté that overlooks the fact that when it comes to policy, ‘transposition does not equal actual implementation’, therefore, there is often a discrepancy between the official state of legal uniformity and the actual facts on the ground.[8]

This essay builds on the work of Nick Andersen and Svein Sitter who criticized the narrow conceptualisation of DI and ‘used the term “differentiated integration” to capture the empirical variation in the impact of EU decisions at the national level.’ They have argued that these variations may be resulting from both ‘formal and informal arrangements.’[9] In order to interrogate this ‘informal’ aspect of DI, it appears intuitive to follow a similar path to those who pinpointed the 2004 ‘big bang’ enlargement as being a crucial stepping stone in the development of DI structures in the EU.[10] Therefore, this essay proposes analysing the impact of the acquis communautaire as many scholars consider the acquis to be the most prominent antithesis to DI and a pinnacle of uniform integration.[11]

The obligation on all new member states to transpose the acquis created the expectation that at the end of the accession process (and after the end of the initial, temporary period of ‘formal’ DI measures) there would be legal uniformity in the areas covered by shared law. However, both the acquis itself and its implementation was marred by issues that prevented it from becoming the ‘great equalizer’ of the Union.

The conceptualisation of the acquis as a Swiss-army-knife of uniformity was detrimental, as within the body of legislation the pattern of detail is ‘highly uneven both across and within policy areas’, therefore, it was immensely difficult to monitor the transposition of the 80,000 odd pages of the acquis.[12]Additionally, the accession process was plagued by shortcomings on the part of the European Commission (EC), leading to an uneven introduction of the acquis.

Scholars have addressed the ‘analytical difficulties’ around assessing the EU’s accession conditionality, however, the limits of this essay only allow for a short discussion of the all-important question of monitoring.[13] During the accession process, the EC’s monitoring procedures utilized a methodology ‘according to which countries are evaluated by the number of measures adopted from detailed Commission “roadmaps” rather than by indicators measuring real changes on the ground.’[14] This roadmap-based approach was worsened by ‘superficial monitoring of candidate states’, and by the fact that ‘performance tasks set for the CEECs [Central and East European countries] by the Commission have not been easily devised, evaluated or benchmarked.’[15] In other words, the EC mistook the ‘transposition of the acquis with a successful outcome of conditionality, without paying attention to the actual implementation.’[16] For DI this meant that while officially, there was no differentiation between member states, this apparent uniformity was nothing more than a sort of Potemkin-uniformity, a uniformity that is ‘more façade than fact.’[17]

One example for this hidden DI can be found in the policy area of regional policy and regionalization as analysed by James Hughes, Gwendolyn Sasse, and Claire Gordon. In their study, the authors have shown that as a result of the relative thin nature of this policy area, outcomes in the East and Central European region were mostly influenced by a variety of domestic factors and led to different outcomes, which undermines the presupposition that the acquis stands for uniformity among member states.[18] Discussing the implications of their study, the authors suggested to leave behind the understanding of conditionality as a ‘constant factor of causation’ and rather conceptualise it as a process resulting in a variety of different outcomes based on ‘the policy area, the actors involved and the candidate country.’ [19] Building on their work, this essay suggests that if the accession process was not the ‘great equalizer’ then one must talk about DI even in the case of the complete transposition of the acquis. Other studies focusing on gender-equality institutions or environmental protection legislation has also underlined the fact, that transposing the acquis did necessarily lead to uniformity among new member states.[20]

This section has showed, how the informal arrangements and the actual implementation of the acquis has been largely neglected in the DI scholarship and argued that the acquis cannot be understood as the a generic tool of uniformity across all member states. This hidden, informal differentiation carries important implications for the future of differentiation and even the very existence of the EU.

The Lasting Impact of Informal Differentiation

The second section argues that neglecting informal arrangements has major implications for the future of the EU, and it might even have a more significant role in understanding DI than formal ‘club memberships.’ As the first section has shown, certain parts of the acquis have not been implemented (only transposed) and have not resulted in lasting change on the ground. Once again, this essay borrows from Andersen and Sitter, who have argued that the considerable variations observable in the impact of EU decisions at a national level can be the product of ‘intended or unintended consequences’.[21] This essay argues that the unintended consequences of the poor implementation of the acquis might have created an ‘excessive fragmentation of the EU polity’, which is generally overlooked.[22] The superficial implementation of the acquis carried implication for the future of differentiation as well, similarly to the scholarly discussion that emerged around the potential centipedal or centrifugal impact of (formal) DI.[23] Akin to debates around the potential lock-in effect of formal DI mechanisms (such as opt-outs), this essay argues that fears from the lock-in of informal DI is well-founded.[24]

While the scale of changes during the accession period cannot be disputed, the lock in effect of the poor implementation of the acquis in certain policy areas might have created unsurmountable differentiation between member states. In cases, when instead of actual implementation, only transposition occurred, the accession procedure locked in ‘deeper structural problems and contradictory behavioural trends.’[25] In her study, Gwendolyn Sasse analysed the impact of minority legislation and found that domestic considerations prevailed over ‘formal’ obligations in cases such as Estonia, and argued that the way conditionality was utilised potentially locked in ‘deeper structural problems and contradictory behavioural trends.[26] Analysing gender equality institutions, Ulrich Sedelmeier has found that non-compliance during the accession processes can lock-in if conditionality is ‘unsuccessful’ – that is to say, if no change is achieved on the ground.[27] This implicates that the formal unity which was achieved with the transposition of the acquis in all new member states not only created a false sense of uniformity among member states but the underlying differences, instead of diminishing and the member states converging toward the common finalité politique, might continue to exist.

Therefore, the neglected area of informal DI is seriously influencing the future shape of the EU. The seminal work of Alexander C-G. Stubb on the various categories of DI states that the multi-speed concept ‘applies to new policy areas only. That is to say, the acquis communautaire is to be preserved and developed.’[28] Other scholars have pointed to the importance of the ‘inviolable’ nature of the common body of legislation.[29] This formulation implicitly understands the acquis as something representing the single-speed nature or the uniform integration of the EU, however, the acquis is not just manifesting itself in a differentiated ways across countries and policy areas, the ‘development’ of the acquis can also face the same problem.

Analysing the transposition of directives in all EU member states, scholars have found that ‘states from Central and Eastern Europe are not doing any worse than the rest of the EU in terms of transposition timeliness.’[30] The fears about an ‘avalanche of infringement cases against the new members after accession’ proved to be unfounded as the new member states were surprisingly compliant.[31] However, as the first section has shown, transposition does not equal actual implementation. One study used the term ‘the world of dead letters’ when discussing the compliance of the majority of ‘new’ EU members, indicating a group who ‘transpose EU Directives in a compliant manner, depending on the prevalent political constellation among domestic actors, but then there is noncompliance at the later stage of monitoring and enforcement.’[32]

These issues indicate a deeper problem with the neglected area of ‘informal’ DI and its future. In the case of European integration, ‘out of sight, out of mind’ is not a fruitful principle and neglecting the existing differentiation between states might have unforeseeable consequences. This section argued that similarly to formal DI, informal arrangements can also lock-in which carry long-term consequences.


This essay shed light on the ‘informal’ aspect of DI through analysing the accession process and more specifically the implementation of the acquis as well as it limits. The first section dissected the shortcomings of the accession process and the ways in which formal transposition covered up the lack of actual change in many cases. The second section analysed the potential future impacts of this informal differentiation and argued that the continued focus on the official transposition of EU legislation only prologues the methodological issue of neglecting facts on the ground. This essay serves as a starting point for future research into the ‘informal’ aspect of DI and puts forward a research agenda that aims to go beyond the official accounts of DI. Exploring this strain of DI at the very heart of the European project may shed light on processes and developments so far unaccounted for by narratives focusing on the legal-institutional aspects of differentiation. However, understanding these processes might just be that is needed to keep differentiated integration from turning into differentiated dis-integration.

[1] Boglárka Koller. ‘Többsebességes vagy menüválasztásos jövő? ‘, in Halmai, Péter (ed.), Tagállami integrációs modellek: A gazdasági kormányzás új dimenziói az Európai Unióban (Budapest: Dialóg Campus, 2019), p. 53.; Benjamin Leruth; Stefan Ganzle; Jarle Trondal. ‘Exploring Differentiated Disintegration in a Post-Brexit European Union’, Journal of Common Market Studies 57 [6] (2019), p.1015.; Iordan Gheorghe Barbulescu and Andra-Maria Popa. ‘A Crisis of the European Model? Reflections and Projections’, in Disintegration and Integration in East-Central Europe: 1919-post-1989 (Baden-Baden, Nomos Verlagshesellschaft mbH, 2014), p. 333. [2] Richard Bellamy and Sandra Kröger. ‘A Demoicratic Justification of Differentiated Integration in a Heterogenous EU’, SSRN Electronic Journal (2017), p. 6. [3] Thomas Malang and Katharina Holzinger. ‘The Political Economy of Differentiated Integration: The Case of Common Agricultural Policy’, The Review of International Organizations 15 (2020), p. 743. [4] S. Svein Andersen and Nick Sitter. ‘Differentiated Integration: How Much Can the EU Accommodate?’ Paper for the 37th World Congress of the International Institute of Sociology, Stockholm, 5-9 July 2005 (2005), p. 4. [5] Boglárka Koller. ‘Klubtagságok az EU-ban: A differenciált integrácó gyakorlati és elméleti vonatkozásai’, Politikatudományi Szemle 21 [1], p. 43. (translation is the author’s); Kenneth Dyson and Angelos Sepos. ‘Differentiation as a Design Principle and as a Tool of Political Management of European Integration’, in Kenneth Dyson and Angelos Sepos (eds.), Which Europe? The Politics of Differentiated Integration (London: Palgrave and Macmillan, 2010), p.11. [6] Alexander C-G. Stubb. ‘A Categorization of Differentiated Integration’, Journal of Common Market Studies 34 [2] (1996), p.284. [7] Quoted in H. J. M. Fenger. ‘Welfare regimes in Central and Eastern Europe: Incorporating Post-Communist Countries in a Welfare Regime Typology’, Contemporary Issues and Ideas in Social Sciences 3 [3] (2007), p. 2. [8]Bernard Steunenberg and Dimiter Toshkov. ‘Comparing Transposition in the 27 Member States of the EU: the Impact of Discretion and Legal Fit’, Journal of European Public Policy, 16 [7] (2009), p. 966. [9] Andersen and Sitter. ‘Differentiated Integration’, p. 12. [10] Dyson and Sepos. ‘Differentiation as a Design Principle’, p. 14; Koller. ‘Klubtagságok’, p. 34. [11] Dirk Leuffen; Rittberger Berthold; and Frank Schimmelfennig. Differentiated Integration: Explaining Variation in the European Union (London: Palgrave Macmillan, 2013), p.17; Dyson and Sepos. ‘Differentiation as a Design Principle’, p.9. [12]James Hughes; Gwendolyn Sasse; and Claire Gordon. ‘Conditionality and Compliance in the EU’s Eastern Enlargement: Regional Policy and the Reform of Sub-National Government’, Journal of Common Market Studies 42 [3] (2004), p. 525. [13] Heather Grabbe. The EU’s Transformative Power – Europeanization Through Conditionality in Central and Eastern Europe (London: Palgrave Macmillan, 2006), p. 31. [14]Alina Mungiu. ‘EU Accession is No “End of History”’, Journal of Democracy 18 [4] (2007), p. 15. [15]Bernd Rechel. ‘What has Limited the EU’s Impact on Minority Rights in Accession Countries?’, EEPS 22 [1] (2008), p. 171.; Hughes, Sasse, Gordon. ‘Conditionality’, p. 526. [16] Rechel. ‘What Has Limited’, p. 183. [17] Wade Jacoby. The Enlargement of the European Union and NATO: Ordering from the Menu in Central Europe (Cambridge: Cambridge University Press, 2010), p. 17. [18] Hughes, Sasse, Gordon. ‘Conditionality, p. 542. and p. 547. [19] Hughes, Sasse, Gordon. ‘Conditionality’, p. 548. [20] Michael Baun and Dan Marek. ‘The Implementation of EU Environmental Policy in the Czech Republic: Problems with Post-Accession Compliance?’, Europe-Asia Studies 65 [10] (2013), pp. 1877-1897 [21] Andersen and Sitter. ‘Differentiated Integration’, p. 12. [22] Thierry Chopin and Christian Lequesne. ‘Differentiated as a Double-Edged Sword: Member States’ Practices and Brexit’, International Affairs 92 [3] (2016), p. 534. [23] Benjamin Leruth; Stefan Ganzle; Jarle Trondal. ‘Differentiated Integration and Disintegration in the EU after Brexit: Risks versus Opportunities’, Journal of Common Market Studies 57 [6] (2019), p. 1385. [24] Dorte Sindbjerg Martinsen and Ayca Uygur. ‘Managing Upward Transfer: On Differentiated Integration in EU Social Policy and the ‘Opt-Out’ Spiral, Department of Political Science, University of Copenhagen [manuscript], p. 9. [25]Gwendolyn Sasse. ‘The Politics of Conditionality: The Norm of Minority Protection before and after EU Accession’, Journal of European Public Policy, 15 [6] (2008), p. 842. [26] Sasse. ‘The Politics of Conditionality’, p. 855. and p. 856. [27]Ulrich Sedelmeier. ‘Is Europeanisation through Conditionality Sustainable? Lockin of Institutional Change after EU Accession’. West European Politics 35 [1] (2012), p. 20. [28] Stubb. ‘A Categorization’, p. 287. [29] Neil Walker. ‘Sovereignty and Differentiated Integration in the European Union’, European Law Journal 4 [4] (1998), p.367. [30] Steunenberg and Toshkov. ‘Comparing Transposition’, p. 951. [31]Ulrich Sedelmeier. ‘After Conditionality: Post-Accession Compliance with EU Law in East Central Europe’, Journal of European Public Policy, 15 [6] (2008), p. 807. [32]Gerda Falkner and Oliver Trieb. ‘Three Worlds of Compliance or Four? The EU-15 Compared to New Member States’, Journal of Common Market Studies 46 [2] (2008), p. 308.

Károly GERGELY, Hungarian freelance journalist and analyst based in Budapest. Károly holds a BA in Politics and Modern History from the University of Manchester and an MSc in Russian and East European Studies from the University of Oxford. A contributor to several outlets, his work focuses on populism, corruption, and the wider Central European and East European region.

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