Daniel E. Herz-Roiphe, Stubborn Things: An Empirical Approach to Facts, Opinions, and the First Amendment
From the intro:
[This] essay reports the results of an original survey that presented respondents with the actual disclosures at issue in a number of recent compelled speech cases, and asked them to categorize these disclosures as factual or opinionated. Participants proved proficient at distinguishing fact from opinion, suggesting that consumer surveys could provide a valuable resource for courts. They also expressed dramatically different understandings of the controversial disclosures at issue in NAM and R.J. Reynolds than the D.C. Circuit did, offering a new and important perspective on how these, and similar, forms of mandated speech should be treated in future litigation.