Fearon's argument regarding the credibility of democratic states in disputes has been subject to debate among international relations scholars. Two studies 2001, using the MID and ICB datasets, provided empirical support for the notion that democracies were more likely to issue effective threats. Survey experiment data substantiate that specified threats induce audience costs, but other data have mixed findings and nuanced findings. A 2019 study found that audiences across the partisan divide had punished Trump, Obama, and "The President" for backing down after issuing threats, but it also found that presidents could reduce the audience costs by justifying the backing down as being in the national interest of the United States. Erik Gartzke and Yonatan Lupu argue that the nature of audience costs (they are a mechanism, not an effect) makes them hard to detect empirically. Kenneth Schultz has also remarked on the methodological difficulties in empirically assessing audience costs. A major problem in assessing audience costs is the fact that leaders typically make threats that are ambiguous in terms of time, place, specific action that trigger the threat, and nature of response. A smoking gun case for audience costs would be a case of the public opposing military action but subsequently punishing a leader for not going through with a threat to engage in military action.
