Russo Williamson Thesis Research Articles

A Dilemma for the Russo–Williamson Thesis

The Russo–Williamson thesis maintains that establishing a causal claim in medicine normally requires establishing both a correlation and a mechanism. In this paper, I present a dilemma for defenders of this thesis: a strong version of the thesis requires denying a plausible counterexample, but as the thesis is weakened, its defenders must give up their favoured account of the explanatory role of causal claims in medicine. I appeal to some recent work in epistemology on infallibilism to propose a way out of this dilemma, where this way out requires neither denying the plausible counterexample nor giving up the favoured account. I think this shows that even apparently abstract debates in epistemology can provide resources that may help to resolve debates in the philosophy of science and medicine.

Taking the Russo-Williamson thesis seriously in the social sciences

The Russo Williamson thesis (RWT) states that a causal claim can be established only if it can be established that there is a difference-making relationship between the cause and the effect, and that there is a mechanism linking the cause and the effect that is responsible for such a difference-making relationship (Russo & Williamson, 2007). The applicability of Russo and Williamson’s idea was hugely debated in relation to biomedical research, and recently it has been applied to the social sciences (Shan & Williamson, 2021). While many philosophers and social scientists have advocated the use of different kinds of evidence for causal discoveries, others have criticised this approach. With this paper, I aim to defend RWT from criticisms and to show its importance in the social sciences. The paper is structured as follows. After a brief introduction, in Sect. 2, I will summarise RWT, and in Sect. 3 I will describe how this approach can be applied to the social sciences. In Sect. 4, I will reconstruct two main criticisms of this thesis proposed in the philosophy of the social sciences literature: namely (i) RWT is not used in the social sciences, (ii) RWT does not work. For each criticism I will provide a defence of RWT. My defence will be based on two general considerations: (i) RWT appears perfectly in line with the research methods used in the social sciences and (ii) RWT can be applied successfully to establish causal claims. In Sect. 5, moreover, I will examine the causal accounts that have motivated such criticisms and I will argue that they should be rejected to endorse RWT and a causal account able to accommodate the current use of mechanistic and difference-making evidence in the social sciences. Section 6 will conclude with a note on the relevance of RWT in both its descriptive and normative form.

Treatment Effectiveness and the Russo–Williamson Thesis, EBM+, and Bradford Hill's Viewpoints

ABSTRACT Establishing the effectiveness of medical treatments is one of the most important aspects of medical practice. Bradford Hill's viewpoints play an important role in inferring causality in medicine, and EBM+ seeks to improve evidence-based medicine, which is influential in establishing treatment effectiveness. At EBM+'s foundations lies the Russo–Williamson thesis (RWT), which can be seen as providing a reduction of Hill's viewpoints into those involving difference-making and mechanistic evidence, both of which are claimed by the RWT's proponents to be typically required for establishing causal claims in medicine. Yet little has been written on whether and how the RWT, EBM+, and Hill's viewpoints establish treatment effectiveness. This could be because of uncertainty over what treatment effectiveness is. I provide an account of treatment effectiveness, analysing the role of the RWT, EBM+, and Hill's viewpoints in this regard. I argue that Hill's viewpoints and EBM+ can be useful in helping to evaluate evidence, but cannot directly establish or confirm treatment effectiveness. This is partly because effectiveness, I claim, is subject to inductive risk and therefore determined by non-epistemic values, neither of which Hill's viewpoints nor EBM+ offer guidance on. I conclude by reinterpreting Hill's viewpoints in light of establishing treatment effectiveness.

Resolving empirical controversies with mechanistic evidence

The results of econometric modeling are fragile in the sense that minor changes in estimation techniques or sample can lead to statistical models that support inconsistent causal hypotheses. The fragility of econometric results undermines making conclusive inferences from the empirical literature. I argue that the program of evidential pluralism, which originated in the context of medicine and encapsulates to the normative reading of the Russo-Williamson Thesis that causal claims need the support of both difference-making and mechanistic evidence, offers a ground for resolving empirical disagreements. I analyze a recent econometric controversy regarding the tax elasticity of cigarette consumption and smoking intensity. Both studies apply plausible estimation techniques but report inconsistent results. I show that mechanistic evidence allows for discriminating econometric models representing genuine causal relations from accidental dependencies in data. Furthermore, I discuss the differences between biological and social mechanisms and mechanistic evidence across the disciplines. I show that economists mainly rely on mathematical models to represent possible mechanisms (i.e., mechanisms that could produce a phenomenon of interest). Still, claiming the actuality of the represented mechanisms requires establishing that crucial assumptions of these models are descriptively adequate. I exemplify my approach to assessing the quality of mechanistic evidence in economics with an analysis of two models of rational addiction.

Standards of evidence and causality in regulatory science: Risk and benefit assessment

In this paper we analyze the Russo-Williamson Thesis (RWT) as a standard of evidence in regulatory science, in risk as well as benefit assessment. In our analysis we take account of the recent controversies that have taken place in regulation with respect to the evidentiary requirements necessary for regulatory decision making. RWT's main point is that not only probabilistic but also mechanistic evidence is necessary for being able to infer the existence of causal links. We ask in which way RWT could have an impact upon current decision making about subjecting to regulation (or, to the contrary, leaving them unregulated) certain chemical substances, food stuffs, health claims, and other typical objects of regulation. We show that the application of RWT resolves some of the problems posed by current standards of evidence. RWT makes it possible to determine with higher accuracy if a particular substance should be subjected to regulation or not, even though under certain circumstances RWT itself may turn into a source of regulatory error. The adequacy of RWT as a standard of evidence depends on the precise manner of its application to regulation (particularly the consideration of mechanistic evidence as a complementary or necessary requirement), as well as the assessment of its non-epistemic consequences.

Evaluating evidential pluralism in epidemiology: mechanistic evidence in exposome research

In current philosophical discussions on evidence in the medical sciences, epidemiology has been used to exemplify a specific version of evidential pluralism. According to this view, known as the Russo–Williamson Thesis, evidence of both difference-making and mechanisms is produced to make causal claims in the health sciences. In this paper, I present an analysis of data and evidence in epidemiological practice, with a special focus on research on the exposome, and I cast doubt on the extent to which evidential pluralism holds in this case. I start by focusing on the claim that molecular data allows for the production of mechanistic evidence. On the basis of a close look at the ways in which molecular data is used in exposome research, I caution against interpretations in terms of mechanistic evidence. Secondly, I expand my critical remarks on the thesis by addressing the conditions under which data is categorised as evidence in exposome research. I argue that these show that the classification of a dataset as a type of evidence is dependent on the ways in which the data is used. This is in contrast with the approach of evidential pluralism, where evidence is classified in different types on the basis of its intrinsic properties. Finally, I come back to what I consider the core of the thesis and suggest that the epidemiological research analysed in the paper indicates different interpretations of evidential pluralism and its applicability in the health sciences.

Establishing Causal Claims in Medicine

ABSTRACTRusso and Williamson [2007. “Interpreting Causality in the Health Sciences.” International Studies in the Philosophy of Science 21: 157–170] put forward the following thesis: in order to establish a causal claim in medicine, one normally needs to establish both that the putative cause and putative effect are appropriately correlated and that there is some underlying mechanism that can account for this correlation. I argue that, although the Russo–Williamson thesis conflicts with the tenets of present-day evidence-based medicine (EBM), it offers a better causal epistemology than that provided by present-day EBM because it better explains two key aspects of causal discovery. First, the thesis better explains the role of clinical studies in establishing causal claims. Second, it yields a better account of extrapolation.

Evidence of mechanism in the evaluation of streptomycin and thalidomide

This paper considers what evidence is needed to establish the effectiveness and safety of a drug therapy. The claim that A cures D is a particular case of a causal claim in medicine. So the paper begins with a general analysis of the evidence for causal claims in medicine. Such evidence is divided into two types: statistical evidence and evidence of mechanism. These are further divided into observational and interventional, producing a 2x2 classification. It is shown that historically there have different assessments of the importance of these different types of evidence. Evidence-based medicine (EBM) puts forward the thesis that claims of the form ‘A cures D without harming the patient’ can be established using only randomized controlled trials or RCTs. This thesis of EBM is criticized by considering two historical examples: streptomycin and thalidomide. Generalizing from these, it is claimed that the effectiveness and safety of a drug therapy can only be established by using both statistical evidence and evidence of mechanism. This is a specific instance of the Russo-Williamson thesis.

Mechanisms and Difference-Making

I argue that difference-making should be a crucial element for evaluating the quality of evidence for mechanisms, especially with respect to the robustness of mechanisms, and that it should take central stage when it comes to the general role played by mechanisms in establishing causal claims in medicine. The difference-making of mechanisms should provide additional compelling reasons to accept the gist of Russo-Williamson thesis and include mechanisms in the protocols for Evidence-Based Medicine (EBM), as the EBM+ research group has been advocating.

Evidence, illness, and causation: An epidemiological perspective on the Russo–Williamson Thesis

According to the Russo–Williamson Thesis, causal claims in the health sciences need to be supported by both difference-making and mechanistic evidence. In this article, we attempt to determine whether Evidence-based Medicine (EBM) can be improved through the consideration of mechanistic evidence. We discuss the practical composition and function of each RWT evidence type and propose that exposure–outcome evidence (previously known as difference-making evidence) provides associations that can be explained through a hypothesis of causation, while mechanistic evidence provides finer-grained associations and knowledge of entities that ultimately explains a causal hypothesis. We suggest that mechanistic evidence holds untapped potential to add value to the assessment of evidence quality in EBM and propose initial recommendations for the integration of mechanistic and exposure–outcome evidence to improve EBM by robustly leveraging available evidence in support of good medical decisions.

The Russo–Williamson Theses in the social sciences: Causal inference drawing on two types of evidence

This article examines two theses formulated by Russo and Williamson (2007) in their study of causal inference in the health sciences. The two theses are assessed against evidence from a specific case in the social sciences, i.e., research on the institutional determinants of the aggregate unemployment rate. The first Russo–Williamson Thesis is that a causal claim can only be established when it is jointly supported by difference-making and mechanistic evidence. This thesis is shown not to hold. While researchers in my case study draw extensively on both types of evidence, one causal claim out of the three analyzed is established even though it is exclusively supported by mechanistic evidence. The second Russo–Williamson Thesis is that standard accounts of causality fail to handle the dualist epistemology highlighted in the first Thesis. I argue that a counterfactual-manipulationist account of causality—which is endorsed by many philosophers as well as many social scientists—can perfectly make sense of the typical strategy in my case study to draw on both difference-making and mechanistic evidence; it is just an instance of the common strategy of increasing evidential variety.

Mechanistic Evidence: Disambiguating the Russo–Williamson Thesis

Russo and Williamson claim that establishing causal claims requires mechanistic and difference-making evidence. In this article, I will argue that Russo and Williamson's formulation of their thesis is multiply ambiguous. I will make three distinctions: mechanistic evidence as type vs object of evidence; what mechanism or mechanisms we want evidence of; and how much evidence of a mechanism we require. I will feed these more precise meanings back into the Russo–Williamson thesis and argue that it is both true and false: two weaker versions of the thesis are worth supporting, while the stronger versions are not. Further, my distinctions are of wider concern because they allow us to make more precise claims about what kinds of evidence are required in particular cases.

Mechanisms, continental approaches, trials, and evolutionary medicine: New work in the philosophy of medicine

Mechanisms, continental approaches, trials, and evolutionary medicine: New work in the philosophy of medicine

On the algebraic variance of linear transformations and its applications to algebraic codes: R.M. Roth and A. Lempel: Department of Computer Science, Israel Institute of Technology, Haifa, Sept. 1986

According to the Russo–Williamson Thesis, causal claims in the health sciences need to be supported by both difference-making and mechanistic evidence. In this article, we attempt to determine whether Evidence-based Medicine (EBM) can be improved through the consideration of mechanistic evidence. We discuss the practical composition and function of each RWT evidence type and propose that exposure–outcome evidence (previously known as difference-making evidence) provides associations that can be explained through a hypothesis of causation, while mechanistic evidence provides finer-grained associations and knowledge of entities that ultimately explains a causal hypothesis. We suggest that mechanistic evidence holds untapped potential to add value to the assessment of evidence quality in EBM and propose initial recommendations for the integration of mechanistic and exposure–outcome evidence to improve EBM by robustly leveraging available evidence in support of good medical decisions.