No – the sign of your correlation doesn’t mean anything either

Here is a generic version of a conversation I’ve had a few too many times: Person 1: “Hey look what I found! My favourite theory is consistent with this correlation. This thing is positively related to that thing.” Person 2: “Good for you! Correlation doesn’t imply causation, though, right?” Person 1: “Of course not, don’t… Continue reading No – the sign of your correlation doesn’t mean anything either

Don’t blame mathematics for the dismal state of the dismal science

Ridiculing the state of economics has been in vogue for quite some time, especially since the last crisis hit. Even before that, we have seen attempts to reform the discipline from students as well as from vocal minorities in the profession. This is a necessary and healthy discussion, and a little bit of new fuel… Continue reading Don’t blame mathematics for the dismal state of the dismal science

Non-linear effects and multiplicative interaction terms? A word of caution.

TL;DR-version: if you’re using multiplicative interaction models and the interacted independent variables are correlated, you have to be extra careful to identify even minor non-linearity in main effects. Interaction effects in various kinds of regression analyses are very common across both the social sciences as well as in, for example, medicine, when we are trying… Continue reading Non-linear effects and multiplicative interaction terms? A word of caution.

Some failed replications: should we blame motivation crowding theory or MTurk?

I wrote last week about motivation crowding theory and in that post I hinted that I’d get back to the subject of replications of this phenomenon. A quick recap: motivation crowding is a phenomenon that can occur if someone, for example, acts in a certain way motivated by pro-social sentiments (other-regard, altruism or the like) and… Continue reading Some failed replications: should we blame motivation crowding theory or MTurk?

Nurture effects in twin studies: distinguishing between “does not” versus “cannot” matter

I may very well be living in an isolated online bubble, but I get the feeling that behavioral genetics is making quite a lot of waves on social media recently. A prominent example is the excellent article “Why parenting may not matter and why most social science research is probably wrong”, by Brian Boutwell, which has been… Continue reading Nurture effects in twin studies: distinguishing between “does not” versus “cannot” matter