Quantifying Non-Tariff Trade Barriers: What Difference Did 9/11 Make to Canadian Cross-Border Shopping?

In this paper I quantify the effect of the tightening of the security precautions post-9/11 on the volume of cross-border shopping from Canada into the United States. Using an extended version of the cross-border shopping model of Ferris (2000), the results suggest that the events of September 11th, 2001, precipitated a drop of between 300,000 and 600,000 same-day cross-border travellers per month or roughly a quarter of the previous volume. [ABSTRACT FROM AUTHOR]