No correlation -> no causation?

I found an interesting variation on the “correlation does not imply causation” mantra in the book Applied Multiple Regression/Correlation Analysis for the Behavioral Sciences by Cohen et al. (apparently one of the statistics bibles in behavioral sciences). The quote (p.7) looks like this: Correlation does not prove causation; however, the absence of correlation implies the absence of the existence of a causal relationship Let’s let the first part rest in peace. At first glance, the second part seems logical: you find no correlation, then how can there be causation? However, after further pondering I reached the conclusion that this logic is flawed, … Continue reading No correlation -> no causation?

Discovering moderated relationship in the era of large samples

I am currently visiting the Indian School of Business (ISB) and enjoying their excellent library. As in my student days, I roam the bookshelves and discover books on topics that I know little, some, or a lot. Reading and leafing through a variety of books, especially across different disciplines, gives some serious points for thought. As a statistician I have the urge to see how statistics is taught and used in other disciplines. I discovered an interesting book coming from the psychology literature by Herman Aguinas called Regression Analysis for Categorical Moderators. “Moderators” in statistician language is “interactions”. However, when … Continue reading Discovering moderated relationship in the era of large samples