2. Overview Empirical generalisations and causal assessment: the manipulationist account The dilemma about manipulationism 1. A conceptual analysis of causation 2. A methodological account of causal assessment (a) Strictly interpreted (b) Charitably interpreted Empirical generalisations and causal assessment without manipulation 2
4. Causal assessment Empirical generalisations Change-relating relations between variables Spurious? Accidental? Invariance Empirical generalisations must show some invariability in order to be causal Intervention Empirical generalisations must be invariant under specified interventions on the cause 4
5. For instance … … in physics: Ideal gas law is invariant under a whole range of interventions on temperature … in biology: The relation between (fictious) gene R and ability to learn and read is not very stable under modification of e.g. schooling or culture 5
8. Identity conditions: X causes Y if, and only if, manipulations on X accordingly yield changes on Y Manipulation is the concept cashing out causation Unilluminating as for the methods for causal assessment To regain coherence of concept and methods: Manipulationist methodology Horn 2 8
10. A method for causal assessment: Were manipulations on X yield changes on Y, then we’d be entitled to infer that X causes Y Another dilemma: Methodological manipulationism can be (a) Strictly interpreted (b) Charitably interpreted 10
11. (a) Strictmethodological manipulationism To know whether X causes Y: 1. perform an intervention on X 2. hold fixed anything else 3. see what happens to Y Typical situation: the controlled experiment Manipulation is a tool to establish causal relations But what if we cannot intervene? E.g., social science, astronomy, … ? 11
12. The manipulationist rebuts: You don’t have to actually intervene: idealmanipulationswill do Not quite: 1. Some ideal interventions don’t make physical sense 2. Some ideal interventions cannot be tested Were we to intervene: a conceptual analysis Stuck back into Horn 1 12
13. (b) Charitablemethodological manipulationism Any sorts of manipulation will do: the agent’s or Nature’s. If Nature manipulates, causal assessment is about evaluating variations in Y due to variations in X Once Nature manipulates, ourtools for causal assessment cannot involve manipulation Back into Horn (a) 2. Manipulation is disingenuously taken as the rationale underpinning causal methods (experimental and non-) See later the reassessment 13
14. Recap Horn 1. A conceptual analysis of causation Unilluminating as to the methods Horn 2. A methodological account of causal assessment a) Strictly interpreted Stuck back into Horn 1 b) Charitably interpreted Stuck back into Horn (a) Disingenuous rationale of causal assessment 14
16. The core of agreement Empirical generalisations reassessed 16
17. Empirical generalisations are change-relating relations between variables Change-relating reflects variational epistemology To be causal, they have to be invariant Not necessarily involving manipulation 17
19. Identity conditions – conceptual analysis Conditions under which a causal claim is true ‘X causes Y’ iff were we to manipulate … Rationale – epistemology/methodology Notion underlying causal reasoning/methods Are there joint variations between X and Y? Are those variations spurious / invariant / regular / due to intervention on X …? 19
21. Invariance doesn’t necessarily require interventions In absence of manipulation: Stability of X-Y relation across chosen partitions of data set, or across different populations Manipulation is not a necessarytool for causal assessment 21
22. To sum up and conclude Causal assessment in manipulationism Empirical generalisations are invariant under manipulations of the cause Manipulationism is trapped in a dilemma Conceptual – lacks methodology part Methodological – too strict or misleading The dilemmadissolves reassessing empirical generalisations Variational epistemology Non-manipulationistinvariance Manipulations are not the building block of causal assessment are a good tool, when they can be performed 22
24. Causal modelling Y = X+ Variational reading Variations in Y are accompanied by variations in X May be just observational. Impose further constraints Manipulationist reading (derived) Manipulations on X make X vary such that Y varies accordingly Joint variations between X-Y are due to manipulations Counterfactual reading (derived) Were we to vary X, Y would accordingly vary Joint variations between X-Y are hypothetical 24
25. On policy interventions Policy interventions are based on causal story: We manipulate because we know that X causes Y Policy intervention do not establish thatX causes Y Although they may lead to revise causal knowledge If the participants in policy making can at least approximate goal consensus, then the next thing they must do is to understand the causal theory that underlies the policy to be implemented. A causal theory is a theory about what causes the problem and what intervention (i.e. what policy response to the problem) would alleviate that problem. Without a good causal theory it is unlikely that a policy design will be able to deliver the desired outcome. Birkland, An introduction to the policy process, 2010 25
26. Manipulation and policy interventions Some form of manipulation occurs in the special sciences too: policy interventions However Policy interventions are designed based on empirical generalisations validated (typically) without interventions Results of policy interventions may lead to further confirmation or to question the validity of the empirical generalization
Editor's Notes
MotivationTo law or not to law. That is the questionFrom physics. We have laws, let’s quarrel on what they are.From biology. It is uncertain that we have laws. Let’s quarrel on whether there are / will / should be any. If so what they are and whether they are (not) the same as physics laws.From the special sciences. Almost certain there aren’t any. Is there any chance they can explain anything at all?Woodward’s solutionYes they can. We don’t need laws. Empirical generalisations do the job. (Let’s specify the characteristics making them causal / explanatory)NeedAssessment of empirical generalisationsMain messageThe current account, based on manipulation, faces troubles