European level: factors coded

National level: factors coded


Coding method 

Example of coding


These factors have been selected in the light of three main limitations described below.

1. The Convergence Index does not include data stemming from national courts

As pointed out above, in drafting the factors, attention was paid to a very important design issue, which has also been the main limitation, namely data availability. Law is not a dataset-friendly field of research, and the challenge was to construe information that could somehow be quantified from available sources. In doing so, the purpose was to isolate the top-down relationship between the European legislator and the CJEU on the one hand, and the national legislator on the other. No quantifiable reference to national case law was included in the set for very practical reasons, such as information asymmetry. The publication of national case law in databases follows non-transparent patterns, making comparisons difficult and potentially too biased to make a significant contribution to the Convergence Index.[1]For this reason, the Index is only limited to the legislative process and does not express any practical application by national courts. The case law of the Court of Justice is however included in the Index for two reasons: (i) it is retrieved from the same transparent source ( and (ii) given the interpretative powers of the CJEU, the case law based on the preliminary reference procedure enshrined in Article 267 TFEU is integrated in the obligations stemming from the Directives themselves.

2. The Convergence Index does not include factors influencing harmonisation by proxy

The second limitation is related to the fact that harmonisation could be affected by factors going well beyond a legislative or judicial process. Examples in this sense include: national legal culture and history (the legal cultural background of a given legal system); consumer empowerment (consumers being aware of their rights); consumer preferences (whether consumers need more or less protection, for more or less expensive goods and services); the number of cases per judge (determining whether case overloads can lead to less awareness of the European nature of a rule, or if it is a sign of resilience to harmonisation by private actors not complying with European standards); judge training (judge awareness of European law developments and applicability in own court); the number of lawyers specialized in European law in relation to the total number of lawyers (practitioner awareness regarding European law developments which can be brought before judges in national disputes). As important as these factors might be, the Convergence Index is limited to the regulatory framework and for this reason it does not look into indicators that might have a social or administrative dimension.

3. The Convergence Index does not have predictive value

One aspect already emphasized above is that the Convergence Index is designed as a quantitative analysis tool that will be used to further explain the legal harmonisation occurring in European consumer sales law. The aim of the Index is to test the extent to which a numerical comparative perspective makes a contribution to the understanding of this process. This entails that any conclusions this Index supports are to be interpreted exclusively in the light of its design and more than anything, its aim. For this reason, the methodology it is based on does not have an inherent statistical nature, but it is rather inspired from statistical methods of data analysis. This mention is necessary to understand that the audience envisioned for this research is not the econometric world (including law and economics scholars), but that of legal academics. In the light of this perspective, the Convergence Index is there to show that legal scholarship can turn to a more numerical evidence-based methodology that adds to the generous amount of classical legal thought.

Having outlined the limitations of the Convergence Index, time has come to look at the actual content of its individual variables. Outlining these variables is essential for the coding of the Index, since for every factor there is an assumption and it is only in the light of these assumption that the entire analysis is to be taken into account. These assumptions operate as rules, or in other words they are the context of the Convergence Index. Outside this context, the conclusions the Index eventually leads to may be misleading.