Lars P. Syll

Are your instrumental variables — really — relevant, exclusive, and exogenous? .[embedded content]

From association to causation .[embedded content]

‘Ideally controlled experiments’ tell us with certainty what causes what effects — but only given the right closures. Making appropriate extrapolations from (ideal, accidental, natural or quasi) experiments to different settings, populations or target systems, is not easy. “It works there” is no evidence for “it will work here”. Causes deduced in an experimental setting still have to show that they come with a transportability warrant to the target population/system. The...

Only the best is good enough . [embedded content] Bille August’s and Ingmar Bergman’s masterpiece. With breathtakingly beautiful music by Stefan Nilsson.

[embedded content] “Non perderti per niente al mondo lo spettacolo di arte varia di un uomo innamorato di te.”

The role of manipulation and intervention in theories of causality As X’s effect on some other variable in the system S depends on therebeing a possible intervention on X, and the possibility of an intervention inturn depends on the modularity of S, it is a necessary condition for something to be a cause that the system in which it is a cause is modular with respect to that factor. The requirement that all systems are modular with respect to their causes...

In Social Science and Medicine (December 2017), Angus Deaton & Nancy Cartwright argue that RCTs do not have any warranted special status. They are, simply, far from being the ‘gold standard’ they are usually portrayed as: Randomized Controlled Trials (RCTs) are increasingly popular in the social sciences, not only in medicine. We argue that the lay public, and sometimes researchers, put too much trust in RCTs over other methods of in- vestigation. Contrary to frequent...

Some methodological perspectives on causal modeling in economics Causal modeling attempts to maintain this deductive focus within imperfect research by deriving models for observed associations from more elaborate causal (‘structural’) models with randomized inputs … But in the world of risk assessment … the causal-inference process cannot rely solely on deductions from models or other purely algorithmic approaches. Instead, when randomization is...

What kind of evidence do RCTs provide? Perhaps it is supposed that the assumptions for an RCT are generally more often met (or meetable) than those for other methods. What justifies that? Especially given that the easiest assumption to feel secure about for RCTs—that the assignment is done “randomly”—is far from enough to support orthogonality, which is itself only one among the assumptions that need support. I sometimes hear, “Only the RCT can control for...

Sex and the problem with interventionist definitions of causation We suggest that “causation” is not univocal. There is a counterfactual/interventionist notion of causation—of use when one is designing a public policy to intervene and solve a problem—and an historical, or more exactly, etiological notion—often of use when one is identifying a problem to solve … Consider sex: Susan did not get the job she applied for because the prejudiced employer took her...