Roger Pielke, Jr.

McGreevy included in the body of the story a bit of a disclaimer: “The HSPC said, however, that it “cannot determine where transmission occurred”. In addition 20 per cent of all cases in the State result from community transmission where the source of the infection is not known.” Of the headline, McGreevy told me, “I didn’t write the headline. I don’t know who did. It would have gone through many iterations with sub-editors etc.”

From there, the statistic traveled around the world. On 5 May 2021 a prominent U.S. observer of public health promoted the statistic on Twitter (below), linking to the Irish Times article and elevating the source to an “analysis.” This Tweet was cited on 11 May 2021 by David Leonhardt of the New York Timeswho further elevated the stature of the statistic to being the result of a “study” with apparently more rigor than other such studies: “A study from Ireland, which seems to have been more precise about the definition of outdoors, put the share of such transmission at 0.1 percent.” Of course, there was no such study.