The effects of terrorism events and changes in the US Homeland Security Advisory System on national park visitation

Christopher R. McIntosh, Neil A. Wilmot, Sichao Wei, David Aadland

Research output: Contribution to journalArticlepeer-review


The impacts of terrorism events and the subsequent Homeland Security Advisory System (HSAS) on visitation to US National Park Service (NPS) sites are examined. A spatial random effects model, using a panel of monthly site visitation (1979–2013), spanning the period between two major terrorism events, is applied. Results show increased visitation after the 1995 Oklahoma City bombing, but a decrease in visitation after 9/11. The decline in park visitation diminishes the farther the park site is from the twin towers, and the more time has passed since 9/11. Elevated terrorism threat levels under HSAS have a negative impact on visitation, but the impact of the warning decays over time. The interaction effect indicates that large visitation sites close to the Twin Towers may experience more visitation after the HSAS level increases. We suggest that the negative HSAS time effect may be due to some potential visitors choosing to stay home, while the positive interaction effect may indicate substitution towards visiting NPS sites.

Original languageEnglish (US)
Pages (from-to)2958-2964
Number of pages7
JournalApplied Economics Letters
Issue number20
StatePublished - 2023

Bibliographical note

Funding Information:
The authors are grateful to the Laborovitz School of Business and Economics for the funding used to hire research assistants and the GIS lab to assist in data collection. The authors also appreciate the support of the Natural Science Foundation of Hunan Province (Grant No. 2021JJ40138) and the Fundamental Research Funds for the Central Universities (No. 023400/531118010241) to run the Matlab codes for the spatial random effects model on the Tencent cloud virtual machines.

Publisher Copyright:
© 2022 Informa UK Limited, trading as Taylor & Francis Group.


  • Visitation
  • national park service
  • terror threat level
  • terrorism


Dive into the research topics of 'The effects of terrorism events and changes in the US Homeland Security Advisory System on national park visitation'. Together they form a unique fingerprint.

Cite this