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Resilient Institutions: The Impact of Rule Change on Policy Outputs in European Union Decision-Making Processes

  • October 20, 2021

by Ariadna Ripoll Servent and Angela Tacea 


The debate on ‘who wins, who loses’ in the European decision-making process is now at a crossroads. On the one hand, the EU supranational institutions (the Commission, the European Parliament [EP], and the European Court of Justice) have been reinforced in successive constitutional treaties; on the other hand, the successive crises, which have affected policy areas close to the sovereignty of member states, have reinforced the role of executives, and favoured non-legislative forms of decision-making. 

In this blogpost, we want to reopen the theoretical and empirical discussions about inter-institutional power dynamics in EU decision-making by looking at an underexploited angle of research, namely the impact of rule change on policy outputs. We reflect on how to theorise rule change, actors' behaviour, and their impact on policy outputs. We also discuss the links between theory and methods, noting the strengths and weaknesses of different methods for the study of institutional and policy change. We draw on the contributions of the Politics and Governance thematic issue to delineate further paths to push forward the current frontiers in EU decision-making research.  


Understanding Rule and Policy Change in EU Decision-Making

We consider that rule change cannot have an independent impact on policy outputs; its influence is mediated by the interpretations and the use that actors make of these new rules (Figure 1). 


Figure 1. How rule change affects policy change.

Figure 1. How rule change affects policy change.

We consider three main sources of rule change. First, formal changes equate to treaty reforms and inter-institutional agreements. The introduction of co-decision in the Treaty of Maastricht and its subsequent modification and expansion in Amsterdam and Lisbon Treaties is a central instance of formal rule change. However, 'interstitial' processes emerging from informal practices in-between treaty changes have often had more pervasive effects than formal changes. A good example is the increase in early agreements and the use of trilogues in co-decision. Informal changes have also been the product of crises that have empowered executive organs such as the European Council, the Commission, the European Central Bank, and EU agencies. 

Rule change may have different types of effects. First, it might introduce new actors into the field, as we have seen with the gradual empowerment of the EP as a co-legislator. Second, it might modify formal competences. The last treaty reforms saw a crucial shift from regulatory competences to EU involvement in core state powers, such as economic and monetary policies, justice and home affairs. Finally, rule change can also act as a window of opportunity, notably when coupled with crises and uncertainty. 

The study of policy change is often unsystematic, making it difficult to compare findings.  What is the status quo? Is it previous EU legislation? What was the status quo before any EU legislation was in place? What is the actual implementation on the ground once EU legislation has been adopted? To what extent has the content of the policies changed (quantity)? And how deep does this change go (quality)? 

Finally, we need to assess whether these (non-)changes can actually be attributed to the (strategic) use of rule change by specific actors since not all policy changes will have their source in rule change. Indeed, rule change is a necessary but not sufficient condition for policy change; therefore, in order to explain outcomes, we need to pay particular attention to the mechanisms of policy change. Policy entrepreneurs might mobilise different types of mechanisms based on actor-centred strategies (e.g., purposefully including or excluding certain actors), ideas (framing solutions, linking issues), and processes (shifting venues, using norms to legitimise certain decisions).  


Studying Rule and Policy Change in EU Decision-Making

Explaining the linkage between rule and policy change requires a broad methodological toolbox. In the past, the effects of changes in formal and informal rules have been dominated by formal modelling and quantitative methods, which have provided general explanations about decision-making but often failed to account for the mechanisms leading to policy change. On the other hand, qualitative studies have remained compartmentalised and often failed to describe the general picture across policy fields.

The study of rule and policy change in EU decision-making has been dominated by game-theoretical and spatial models. Formal models have contributed greatly to the understanding of the different EU legislative procedures, the power of the EU institutions, and the degree of gridlock. However, they have often failed to take the increased informalisation of EU legislative procedures into account and have tended to treat EU institutions as homogenous actors. Some of these caveats have been addressed by quantitative and qualitative studies. However, on the one hand, one of the main difficulties in using quantitative methods to study rule and policy change comes from the availability and quality of data. Indeed, formal powers, partisan ideologies, and parliamentary amendments provide only an approximation of influence or policy positions, as they do not capture, for example, informal negotiations, and they often measure only the revealed/strategic preferences of actors. On the other hand, most qualitative studies are case studies examining very salient EU proposals and focusing on new areas of EU activity, which limits their generalisability beyond their policy field.


Contributions of The Thematic Issue

The contributions of the thematic issue offer significant insights on the effects of rules change on policy change by combining quantitative and qualitative perspectives. Most contributions depart from Lisbon as the most significant turning point for the EU's architecture in the last decades. The expansion of co-decision and consent have made a significant difference, both in formal and informal terms (Gravey & Buzogány, 2021; Laloux & Panning, 2021; Peffenköver & Adriaensen, 2021; Piquet, 2021; Tacea, 2021). When it comes to the mechanisms of change, we see how rule changes have indeed led to new forms of competition that force us to assess winners and losers beyond the traditional institutional triangle. Several contributions show that the Commission is now more dependent on the EP, which has led to new forms of early consultation and cooperation in formal procedures (Gravey & Buzogány, 2021; Peffenköver & Adriaensen, 2021). We also see how politicisation has become crucial to explain the role of actors in proactively using the decision-making process to bias or block policy change (Vinciguerra, 2021). By using quantitative, qualitative, and text-mining techniques, the thematic issue bridges the gap between empirical case studies and large-N analyses. The contributions demonstrate that there is a need to strengthen the dialogue between institutionalists and policy analysts but also between formal modellers, quantitative, and qualitative researchers to gain a better understanding of the patterns and mechanisms of change and stability in EU decision-making.


* This post is a shorter and adapted version of the original article published in Politics and Governance Special Issue: ‘Resilient Institutions: The Impact of Rule Change on Policy Outputs in European Union Decision-Making Processes’ (2021, Volume 9, Issue 3). The original version can be accessed here.


  • Ariadna Ripoll Servent: Salzburg Centre of European Union Studies, University of Salzburg, Austria; E-Mail: 

  • Angela Tacea: Institute for European Studies, Vrije Universiteit Brussel, Belgium; E-Mail:


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