One and a half years ago, I blogged about a working paper by Simen Markussen, Knut Røed and myself showing that access to commercial television channels during childhood and adolescence reduced cognitive ability scores and high school graduation rates of Norwegian men. Now, a substantially revised version is forthcoming in The Journal of Human Resources. (Preprint here.) The effects appear to be driven by consumption of light television entertainment crowding out more cognitively stimulating activities.
Bears repeating: Pat Sharp tweets an apology (thanks to @JFiva).