Table 1.

Operationalization of sub-indices.

Sub-indices	Raw data	Baseline (equal to 100)	Data source	Included in overall index
Aviation	Daily departure data from a country's international airports	Year-over-year adjusted data (Eq. (1))	https://www.icao.int/safety/Pages/COVID-19-Airport-Status.aspx	Yes
Hotel	Daily data on a country's hotel RevPAR	Year-over-year adjusted data (Eq. (1))	STR, LLC	Yes
Pandemic	Daily number of confirmed COVID-19 cases per 1 million inbound tourists in 2018	1 confirmed case per 1 million inbound tourists or less	World Development Indicators; https://www.ecdc.europa.eu/en/publications-data/download-todays-data-geographic-distribution-covid-19-cases-worldwide	Yes
Interest	Daily Google search volume for keyword “[country name] hotel”	Jan 3–Feb 6, 2020	Google Trends	No
Mobility	Daily Google community mobility data in locations of “Retail and recreation,” “Parks,” and “Public transport”, which are directly related to travel and tourism.	Jan 3–Feb 6, 2020	https://www.google.com/covid19/mobility/	No