Stefan Theil: Missing the Forest for the Trees – Deficits in Doctrinal Methods and How Data Can Help


Law and legal scholarship have a problem: a problem with digesting and analysing the sheer volume of decisions reached every year by domestic and international judicial bodies. From January to March 2021 alone, Her Majesty’s Courts & Tribunals Service (HMCTS) recorded 72,000 receipts and disposed of as many cases, with an outstanding caseload of 622,000. The European Court of Human Rights (ECtHR) issues tens of thousands of decisions annually and in 2020 had a backlog of approximately 62,000 pending applications.

Despite these stark figures and the wide availability of online legal databases, doctrinal research has remained largely unchanged since the introduction of systematic reporting of court decisions. While there is a general awareness of the massive number of potentially relevant decisions on any particular legal question, lawyers all too often turn towards a problematic legal fiction embodied in the idea of ‘landmark’ (‘controlling’ or ‘leading’) cases.

The concept is the ubiquitous coping mechanism that is employed by virtually all members of the legal profession, and its basic defining characteristics are intuitively recognised: they are the small subset of cases that shape our understanding of the law and constitute major doctrinal developments. Their citation and recitation in skeleton arguments, judgments, consultations, exams, and legal opinions of every stripe ensure they remain at the forefront of attention and their analysis in scholarship teases out ever more sophisticated nuances of significance.

The legal fiction lies in assuming that these are the most important cases, perhaps the only ones that need to be seriously considered to understand the law. Given this great significance and influence, surprisingly little attention is paid to why certain cases, and not others, enter the cannon of doctrinal reasoning and attain the status of ‘landmarks’. Assumptions about relevant criteria, methodology, and metrics are rarely made explicit or critically evaluated, with problematic outcomes.

The government consultation on Human Rights Act Reform singled out certain ‘landmark’ decisions for discussion and criticism as supposed overreaches by the European Court of Human Rights (ECtHR), including Hirst v The United Kingdom (No.2) and Hatton v United Kingdom which were both discussed at considerable length. Both cases are certainly widely perceived as doctrinally significant but their historic and modern relevance has scarcely been subject to meaningful interrogation. It may well be that nothing in particular turns on these cases and the focus on them is therefore not only unwarranted, but actively distorts the state of the law (a critique of Hatton along those lines can be found in chapter 7 of Towards the Environmental Minimum, CUP 2021).

This is particularly concerning where an inaccurate account of the law grounds proposals for legislative reform. The Independent Human Rights Act Review (IHRAR) devoted considerable attention to supposed landmark cases to elaborate legal doctrine and underpin their recommendations. The decisions in Osborn v Parole Board [2013] UKSC 61 and Kennedy v Charity Commission [2014] UKSC 20 are expressly recommended for codification, while Beard v the United Kingdom is presented as solitary authority on the relevance of precedent in the ECHR system. Seemingly no attempt is made to critically question why these cases, and not others ought to form the basis for reforms.

Even where attempts are made to engage with relevant contextual data, these can be mired by a flawed methodology, as was the case with the Independent Review of Administrative Law (IRAL). As Mikołaj Barczentewicz showed on this blog, the IRAL data analysis drew empirically indefensible conclusions on the success rate of Cart judicial review proceedings that were subsequently relied upon by the government.

To an extent what makes a ‘landmark’ case is not an empirical question, but one that lies in the eye of the beholder: especially influential scholars and judges have always had a disproportionate impact on shaping our understanding of the law. The main problem is not the irreducible subjective element, or the influence as such, but the limited sampling of relevant cases that informs such determinations and that the practice of ‘landmarking’ encourages. Assessments of what counts as an important case are often too strongly influenced by what others have deemed significant in the past. Conventional doctrinal research without contextual data thus risks missing crucial pieces of the puzzle: important cases that may have been overlooked for one reason or another but are no less significant than their ‘landmark’ brethren.

This contribution suggests we critically re-visit doctrinal methods to address this problem. It sketches a methodology that returns ‘to the basics’ of doctrinal scholarship, but with an empirical twist enabled through modern database technology. The benefits of this methodology are illustrated by telling the cautionary tale of the ECtHR decision in López Ostra v. Spain through the lens of a comprehensive dataset of all ECHR environmental decisions. On this basis, the relevance and impact of López Ostra is less empirically and doctrinally clear than conventionally accepted. While the case study is only about one environmental case, its conclusions, in my view, reach far beyond this limited context.

If this appears at all controversial, then it should not. The contribution merely systematises and updates doctrinal methodology for the age of data: it ensures proportionate engagement with all available cases and gives conventional doctrinal methods their proper role in determining relevancy, while avoiding undue focus on cases already lavished with attention. This exercise may well confirm widely held views on the ‘landmark’ status of particular cases, or it may chip away at a dominant view that perhaps crystalized prematurely.

Acquiring the Data

The initial dataset was obtained through the hudoc search engine provided by the European Court of Human Rights. The database was searched using a Boolean search which returned a combined total of 3091 hits for specific environmental keywords. Cases were then manually examined to confirm their environmental nature. The dataset includes all cases available through the search engine on 31 December 2019.

However, it must be treated with a degree of caution when assessing cases originating from less than eight years ago. The median time taken from initial application to final decision in any given year is 50 months, just over 4 years. Given the dataset cut-off date of 31 December 2019, a majority of cases originating from between 2015 and 2019 had not yet been resolved at this stage. Consequently, the framework of reference for this contribution is limited to the years up to and including 2014. The dataset, along with a detailed explanation of methodology and methods is freely available for educational and research purposes here.

López Ostra

The applicant in López Ostra lived in a city with a high density of factories specializing in the treatment of leather. A waste treatment plant had begun operating in 1988, without a license and contrary to domestic law, only twelve metres’ distance from the applicant’s home. Several incidents at the plant led to significant contamination, constituting severe public health problems through gas fumes and ‘pestilential smells’ [8]. Local residents, including the applicant, were evacuated and the plant was ordered to partially shut down. The remaining operation, however, continued to pose significant health risks from 1991 through 1993, as evidenced by expert opinions [9]. The applicant complained that the inaction of local authorities violated her rights under Articles 3 and 8 ECHR. The Court accepted the claim, particularly given that the emissions exceeded the domestic legal limits and posed a substantial danger to human health. The state had failed to strike a fair balance between the economic well-being of the town and the respect for her rights resulting in a violation of Article 8 ECHR [55].

Over the years an almost universal view emerged that López Ostra was a pivotal decision for the development of environmental human rights under the ECHR. However, the dataset shows that the Convention entities issued 32 decisions in environmental cases prior to 1994: violations were found in six of these cases, three settled and the remaining 23 were dismissed. While López Ostra certainly has its place in the canon of environmental human rights law, significant doctrinal developments in two cases precede it by almost a decade: Arrondelle v. United Kingdom (1982), Baggs v. United Kingdom (1985).

The Precursors

In the case of Arrondelle both the runway of Gatwick Airport and the M23 motorway were extended to encroach within a few hundred feet of the applicant’s home. An independent inspector determined that this led to ‘intolerable stress by reason of the intensity, duration and frequency of the noise primarily from low flying aircraft passing almost overhead.’ Unsurprisingly, attempts to sell the property proved futile. The case was ultimately settled during the course of these proceedings [4]. The local Council agreed to purchase the home at its current market value and the difference to the unblighted value of the property was paid by the UK Government.

The facts in Baggs were largely similar to those in Arrondelle, although the noise levels endured were considerably worse and originated from Heathrow Airport. The independent Eyre Report on Heathrow Air Noise noted the intolerable conditions experienced by the applicants.

The core argument of the UK was that it was not responsible for the noise emissions caused through the conduct of third-party aircraft operators. Instead, the Commission deemed the direct cause of the noise emissions immaterial and held the state responsible by way of its planning and regulatory authority. The proceedings in Baggs were likewise settled, but not before being joined with two other applications considered by the Commission: Powell and Rayner v United Kingdom. The latter proceeded to the Court, but as the claims under Article 8 ECHR had been previously dismissed by the Commission they were not examined further under this provision [25]. Jointly, these cases were important precursors to López Ostra in three respects.

First, they represent the first cases where the Commission engages constructively with environmental degradation under the Convention. While it is correct that Baggs and Arrondelle were settled, the cases nonetheless ensured that environmental applications were taken seriously. Environmental concerns became firmly established as relevant and potential infringements of Convention rights. The dismissive attitude of earlier decisions in Dr S v Germany (App no 715/60, Commission, 5 August 1960, unpublished, on file with author) and X and Y v Germany was overcome and states began to take notice. They could no longer rely on an outright refusal to hear environmental cases and at least some friendly settlements appear to be motivated by a desire to avoid an adverse precedent.

Second, states were consistently held responsible for environmental degradation arising from the conduct of third parties. It was largely immaterial that the aircraft were operated by private airlines: states were responsible by way of their oversight and regulatory authority. Before the aircraft noise cases, this was far from a settled view. In Rayner, the Commission cites Marckx v Belgium as the sole authority for the proposition that states are directly responsible for private actors under the Convention. However, Marckx does not deal with environmental degradation and is better understood as supporting the notion of general positive obligations arising from Article 8 ECHR. The case was less concerned with attributing direct responsibility for the actions of private actors.

Third, the cases held Article 8 ECHR admissible and accepted, to varying degrees, that infringements could arise from environmental degradation. Even if no violations were ultimately found, these decisions opened the door to the modern environmental protection under the Convention. Notably, the absence of any requirement for the applicants to demonstrate specific health detriments as a result of the environmental harm. None of these cases of course diminish the role that López Ostra had as the first case explicitly finding a violation on environmental grounds. However, but for the settlements, we may well have seen this development much earlier.

Mapping the Data Impact

Moreover, at least with respect to absolute and relative increases in environmental cases filed, decisions issued, and violations found, claims that López Ostra sparked a deluge of environmental litigation are not borne out by the data.

Figure 1 below demonstrates that there is no significant rise in the number of environmental cases filed in the following years: from 1995-2001 there are only modest fluctuations. Much the same can be said for the number of violations found in the same time period, which remained largely consistent. By contrast, a significant spike in applications filed, decisions issued and violations occurs in 2002. The number of applications filed reaches an unprecedented level (sixteen) and leads to a higher sustained level for a longer period, in contrast to a similar spike in 1985. Moreover, in the years immediately after 2002, there is a sustained increase in the number of violations found. Given the year of the decision in López Ostra (1994), this effect cannot be easily attributed to the case.

A possible rebuttal to this interpretation of the dataset would argue that the data masks an increase in environmental cases relative to overall cases. Again, analysis of the data represented in Figure 2 below demonstrates that the relative number of environmental cases drops after López Ostra, leading to a general downward trend from 2.3 environmental applications filed per thousand cases in 1995 to only 0.05 filed in 2013. This is in part attributable to the increase in overall (i.e. including non-environmental) applications filed following the reforms introduced by Protocol 11 to the ECHR represented in Figure 3. Crucially, the Protocol abolished the Commission and expanded access by rendering mandatory the previously optional right of individual petition to the Court.

The case it seems for an inundation of environmental applications following the decision in López Ostra is not a strong one.

We can now move on to the number of references made to López Ostra in subsequent decisions as a further possible proxy for impact. López Ostra has been cited in 60 subsequent environmental cases, Hatton has been cited in 40 (combined references to Chamber and Grand Chamber decision) and Guerra in 39 (combined references to Chamber and Grand Chamber decision). At first glance, this makes all three cases significant as the average number of citations for environmental decisions is only approximately 4.46. However, as previously mentioned, it is worth looking beyond the frequency of references for deeper signs of impact that can test the notion of singular importance often associated with López Ostra. While references to López Ostra track the number of violations found in environmental cases quite well, the decision was not invariably referenced when finding violations. Figure 4 below gives the number of decisions that cited López Ostra in relation to cases where violations were found and the overall number of environmental cases in a given year from 1994 (the year of the decision) to 2013.

A similar picture emerges when we compare the citations of López Ostra with those of Hatton and Guerra over the same time period (Figure 5).

López Ostra is roughly tied with Guerra once the latter decision is issued in 1998 until 2003, when the Chamber ruling in Hatton is handed down. All three cases receive an almost identical number of citations form there onwards. Attention and impact, it seems, are evenly split amongst these three cases, with the higher overall number of references to López Ostra chiefly explained through the earlier date of the decision.

Against this backdrop, the impact of López Ostra appears more ambivalent than the literature would suggest. Even if a significant domestic delay existed, as suggested in the previous section, the fact remains that López Ostra had no discernible impact on the number of violations found in environmental cases. The ECtHR was not short on applications to which it might have applied the doctrinal position developed in the case. Moreover, as Figure 4 demonstrates, despite the rise in environmental applications filed, this does not result in a subsequent spike in the number of decisions that reference López Ostra. They remain fairly stable throughout the years. By contrast, the case for a broader impact of López Ostra beyond the four years following the decision are stronger: the case is frequently cited and there was a considerable rise in environmental applications in 2003 that is sustained in the following years. Overall therefore, the empirical picture is a mixed one: some factors speak to the significance of López Ostra, while others caution against this interpretation.

The innovations and significance ascribed to López Ostra appear more ambivalent given this context. The contribution offers an updated assessment that better accounts for the available data and doctrinal evidence, however, it cannot claim to authoritatively settle the question of significance for all intents and purposes. Certainly, there are some features of this dataset and analysis that are idiosyncratic: it discusses one particular environmental case under the ECHR, an admittedly small drop in the vast doctrinal ocean. However, beneath the surface it explores a deeper problem with doctrinal methods, a coping mechanism that virtually all lawyers employ where cases decided far outstrip capacity for individual doctrinal analysis. It has led countless decisions being hailed as crucial landmarks and their stories told and retold in articles, books, skeleton arguments, reports, and proposals for legislative reforms.

This approach has understandable historic roots but risks that views about the significance of cases crystalize prematurely. We might build our understanding of the law around cases that are in fact insignificant on their own terms, that merely restate significant propositions developed in other cases, or when viewed in context simply do not support the propositions for which they are invoked.

The danger is not simply that we become distracted by unimportant cases, but that we get the state of the law profoundly wrong: we fail to accurately assess, predict, and guide its development and miss out on the contexts and nuances that make convincing legal arguments. In other words: we define the law on the basis of the seemingly solitary tree with only sporadic attempts to systematically examine and situate it in the doctrinal forest. Serious legal research, proposals for legislative reforms, scholarly papers, as well as the advice we offer to our clients cannot be blind to this shortcoming, or remain indifferent to its implications: a deeper and richer analysis that combines rigorous doctrinal research with data is eminently feasible and profoundly necessary.

Stefan Theil is John Thornley Fellow and Director of Studies in Law at Sidney Sussex College, University of Cambridge

The post is based on Excavating Landmarks – Empirical Contributions to Doctrinal Analysis, which first appeared in (2020) 32 Journal of Environmental Law 221. The data analysis was refined in my book Towards the Environmental Minimum (Cambridge University Press, 2021). The dataset of environmental decisions, along with a detailed methodological appendix is freely available for educational and research purposes here. I am grateful to Alison Young and Michael Gordon for helpful feedback on earlier drafts.

(Suggested citation: S. Theil, ‘Missing the Forest for the Trees – Deficits in Doctrinal Methods and How Data Can Help’ U.K. Const. L. Blog (3rd February 2022) (available at: