You probably couldn't find much evidence re Krugman + Charlatan, because he's not. He's an accomplished economist who's influential and respected among the academic community. He's won two of the most prestigious awards in economics (Nobel + John Bates Clark). He's had some peculiar arguments in the past, which were dumb imo, but nothing "Charlatan"... Science is hard and economics is unique. Krugman is known for doing post-mortems and admitting when his ideas are off. I also think that being recognized by the academic community and his peer economists is a reasonable signal that he's not an idiot.

More recently he's been a bit more into hackish punditry and is prob. most famous among regular people for his somewhat abrasive nyt column. I think your idea about and API is not ideal. Is it enough to trust some randos on hacker news to identify Charlatans?