In the 1950s and 1960s, an interfield interaction between molecular biologists and biochemists integrated important discoveries about the mechanism of protein synthesis. This extended discovery episode reveals two general reasoning strategies for eliminating gaps in descriptions of the productive continuity of mechanisms: schema instantiation and forward chaining/backtracking. Schema instantiation involves filling roles in an overall framework for the mechanism. Forward chaining and backtracking eliminate gaps using knowledge about types of entities and their activities. Attention to mechanisms highlights salient features of (...) this historical episode while providing general reasoning strategies for mechanism discovery. (shrink)

Ever since David Hume, empiricists have barred powers and capacities from nature. In this book Cartwright argues that capacities are essential in our scientific world, and, contrary to empiricist orthodoxy, that they can meet sufficiently strict demands for testability. Econometrics is one discipline where probabilities are used to measure causal capacities, and the technology of modern physics provides several examples of testing capacities (such as lasers). Cartwright concludes by applying the lessons of the book about capacities and probabilities to the (...) explanation of the role of causality in quantum mechanics. (shrink)

In addition to the notion of causal law, the concept of capacity, modelled on Mill's notion of tendency, is required to make sense of standard methods in econometrics and standard accounts of probabilistic causality. General causal claims are shown to be ascriptions of capacities while causal laws are local causal claims, relative to a test population. Capacities are at a higher level of modality and are not reducible to causal laws, as causal laws are not reducible to laws of association (...) that describe mere regularities; but unlike laws of association, capacities are real. (shrink)

WE AIM HERE to outline a theory of evidence for use. More specifically we lay foundations for a guide for the use of evidence in predicting policy effectiveness in situ, a more comprehensive guide than current standard offerings, such as the Maryland rules in criminology, the weight of evidence scheme of the International Agency for Research on Cancer (IARC), or the US ‘What Works Clearinghouse’. The guide itself is meant to be well-grounded but at the same time to give practicable (...) advice, that is, advice that can be used by policy-makers not expert in the natural and social sciences, assuming they are well-intentioned and have a reasonable but limited amount of time and resources available for searching out evidence and deliberating. (shrink)

Employing a well-known local regularity from macroeconomics, the Phillips curve, I examine Woodward’s ([2000], [2003]) account of the explanatory power of such historically restricted generalizations and the mathematical models with which they are sometimes associated. The article seeks to show that, pace Woodward, to be explanatory such generalizations need to be underwritten by more fundamental ones, and that rational choice theory would not avail in this case to provide the required underwriting. Examining how such explanatory restricted regularities are underwritten in (...) biology—by unrestricted Darwinian regularities—provides the basis for an argument that Darwinian regularities serve the same function in human affairs. The general argument for this claim requires, inter alia , that we accept some version or other of a theory of memes. The article concludes by clearing the field of some prominent objections to the existence of memes, and extracting some policy implications from the persistence and acceleration of arms races in human affairs. (shrink)

The claims of RCTs to be the gold standard rest on the fact that the ideal RCT is a deductive method: if the assumptions of the test are met, a positive result implies the appropriate causal conclusion. This is a feature that RCTs share with a variety of other methods, which thus have equal claim to being a gold standard. This paper describes some of these other deductive methods and also some useful non-deductive methods, including the hypothetico-deductive method. It argues (...) that with all deductive methods, the benefit that the conclusions follow deductively in the ideal case comes with a great cost: narrowness of scope. This is an instance of the familiar trade-off between internal and external validity. RCTs have high internal validity but the formal methodology puts severe constraints on the assumptions a target population must meet to justify exporting a conclusion from the test population to the target. The paper reviews one such set of assumptions to show the kind of knowledge required. The overall conclusion is that to draw causal inferences about a target population, which method is best depends case-by-case on what background knowledge we have or can come to obtain. There is no gold standard. (shrink)

_Conjectures and Refutations_ is one of Karl Popper's most wide-ranging and popular works, notable not only for its acute insight into the way scientific knowledge grows, but also for applying those insights to politics and to history. It provides one of the clearest and most accessible statements of the fundamental idea that guided his work: not only our knowledge, but our aims and our standards, grow through an unending process of trial and error.

Proponents of evidence-based medicine and some philosophers of science seem to agree that knowledge of mechanisms can help solve the problem of applying results of controlled studies to target populations (‘the problem of extrapolation’). We describe the problem of extrapolation, characterize mechanisms, and outline how mechanistic knowledge might be used to solve the problem. Our main thesis is that there are four often overlooked problems with using mechanistic knowledge to solve the problem of extrapolation. First, our understanding of mechanisms is (...) often (and arguably, likely to remain) incomplete. Secondly, knowledge of mechanisms is not always applicable outside the tightly controlled laboratory conditions in which it is gained. Thirdly, mechanisms can behave paradoxically. Fourthly, as Daniel Steel points out, using mechanistic knowledge faces the problem of the ‘extrapolator’s circle’. At the same time, when the problems with mechanistic knowledge have been addressed, such knowledge can and should be used to mitigate (nothing can entirely solve) the problem of extrapolation. (shrink)

The Description for this book, Theory and Evidence, will be forthcoming.

Hunting Causes and Using Them argues that causation is not one thing, as commonly assumed, but many. There is a huge variety of causal relations, each with different characterizing features, different methods for discovery and different uses to which it can be put. In this collection of new and previously published essays, Nancy Cartwright provides a critical survey of philosophical and economic literature on causality, with a special focus on the currently fashionable Bayes-nets and invariance methods - and it exposes (...) a huge gap in that literature. Almost every account treats either exclusively how to hunt causes or how to use them. But where is the bridge between? It's no good knowing how to warrant a causal claim if we don't know what we can do with that claim once we have it. This book will interest philosophers, economists and social scientists. (shrink)

Inferences like these are known as extrapolations.

This book provides a methodological perspective on understanding the essential roles of econometric models in the theory and practice. Offering a comprehensive and comparative exposition of the accounts of models in both econometrics and philosophy of science, this work shows how econometrics and philosophy of science are interconnected while exploring the methodological insight of econometric modelling that can be added to modern philosophical thought. The notion of structure is thoroughly discussed throughout the book. The studies of the consumption function of (...) Trygve Haavelmo, Richard Stone, Milton Friedman, David Hendry and Robert Lucas are taken as the case studies to investigate their methodological implications of model and structure. In addition to the semantic view of the scientific theories, various philosophical accounts concerning scientific models are used to shed light on the methodological nature of these consumption studies in economics. This book will be of great interest to scholars and students of methodology of economics and econometrics as well as anyone interested in the philosophy of science in an economic context. (shrink)