Table 2.

Elements of norm-based message presented to respondents of the four treatments.

Item	Text	1	2	3	4
Introduction	Now the final questions about vaccines against COVID-19.	x	x	x	x
Main	From a previous study, conducted between June 9 and July 7, 2021, we know that in Rome the percentage of people in favor of vaccination against COVID-19 is high.		x	x	x
Empirical	81% of the people expressed the wish to get vaccinated or already received the vaccine (one or two doses).		x		x
Normative	76% of the people consider the behavior of someone who decides not to get vaccinated between slightly and extremely inappropriate.			x	x