Respiratory mortality is the mortality from the H1N1 ("Swine Flu") pandemic in 2009 estimated by Simonsen et al. (2013). Incoming trips is the number of people arriving in each country, for any duration of stay, per resident in 2008. For details on the variable's construction, see Section 3.3 of "Global Mobility and the Threat of Pandemics: Evidence from Three Centuries" (Clemens and Ginn, 2020).