In addition to providing Harvard with the services of a professional economist, Mankiw also provides TV shows with a media personality, and political campaigns with consulting. He is good at all 3 jobs, but they do sometimes entail different things. Consequently “Mankiw said X” and “Mankiw said X in an article intended for publication in an academic journal” provide very different levels of evidence.
In addition to providing Harvard with the services of a professional economist, Mankiw also provides TV shows with a media personality, and political campaigns with consulting. He is good at all 3 jobs, but they do sometimes entail different things. Consequently “Mankiw said X” and “Mankiw said X in an article intended for publication in an academic journal” provide very different levels of evidence.