How much does violence tax trade?

We investigate the empirical impact of violence as compared to other trade impediments on trade flows. Our analysis is based on a panel data set with annual observations on 177 countries from 1968 to 1999, which brings together information from the Rose [2004] dataset, the ITERATE dataset for terrorist events, and datasets of external and internal conflict. We explore these data with traditional and theoretical gravity models. We calculate that, for a given country year, the presence of terrorism, as well as internal and external conflict is equivalent to as much as a 30 percent tariff on trade. This is larger than estimated tariffequivalent costs of border and language barriers and tariff-equivalent reduction through GSPs and WTO participation.