Improving the Accuracy of Outbound Tourism Statistics with Mobile Positioning Data Ossi Nurmi 15th Global Forum on Tourism Statistics, Cusco, Peru November 2018

Introduction What is it? Outbound tourism means visits by the residents of a country to another country Why is it important? Accurate outbound tourism statistics are important for international trade in services and balance of payments statistics So what’s the matter? Outbound tourism data are typically collected by surveys, typically CATI or CAWI Alternative or complementary data sources are needed because survey small sample sizes are small and survey response rates are declining What about mobile positioning then? Mobile network operators (MNOs) store ’traces’ of the mobility of people In outbound tourism, these traces are roaming events (calls, sms, data) of mobile devices used in a foreign country They can be translated into outbound trips from a country to all other countries

Data process OPERATOR 1 S T A I C F N L D PROCESSED RAW DATA SUBSCIBER ID TRIP ID TRIP DURATION MONTH COUNTRY CODE AGGREGATE DATA YEAR MONTH COUNTRY TYPE OF TRIP DURATION NUMBER OF TRIPS RAW DATA SUBSCRIBER ID COUNTRY CODE EVENT TIME OPERATOR 2 RAW DATA PROCESSED RAW DATA AGGREGATE DATA The data process was established by Statistics Finland during 2016 – 2018 as part of Eurostat’s ESSNet Big Data Project Only MNOs are allowed to process their data using automatic means in the current legislation

Mobile roaming events and trips Roaming events = calls, sms or data in a mobile network abroad First event indicates beginning of trip to a country The end of trip is determined based on time gaps and following events In this example, 5 outbound trips identified during the 30 day period 2 day trips 2 short trips (1-3 nights) 1 long trip (over 3 nights)

Top down approach for data validation Finnish Travel –survey Mobile Positioning Data Sample size 28,500 persons < 70% of population Outbound trips observed < 3,000 per year < 7 million per year Average weight of one outbound trip < 4,000 < 1.3 Total number of outbound trips in 2017 10.5 million

Top down validation: number of trips Estonia and Sweden nearly half of all outbound tourism MNO data provides 24% less trips to Estonia 44% more trips to Sweden Some countries are exaggerated and others underestimated Conclusion: Number of trips in the MNO data is biased depending on country Possible reasons include: Non-tourism trips Border noise Phones switched off or not used Sample bias (one MNO missing)

Top down validation: monthly seasonality Conclusion: monthly survey estimates are affected by randomness. MNO data provides a more accurate monthly seasonality.

Strengths and weaknesses Finnish Travel -survey Mobile positioning data Strengths Scope is clean: only tourism trips are included Provides supporting information of the trip (ie. purpose of trip, expenditure, means of transport and accommodation) Granularity: millions of trips covering nearly all destination countries Monthly seasonality of tourism is more accurate Weaknesses Granularity: very few observations per year, covering only a few destination countries Monthly seasonality estimates are affected by randomness Scope is not clean, there are many sources of over- or underestimation No supporting information of the trip

Proposed method for improving survey data Use the total number of annual outbound trips from the (Finnish Travel) survey as the frame Determine the (95%) confidence intervals for each destination country Select the more reliable source data (survey or MNO data) for outbound trips separately for each destination country. Calculate a coefficient factor for trips to those countries that will be based on MNO data Apply the monthly seasonality trend based on MNO data separately for each country

Confidence intervals for number of trips

2017 results by country Top 10 countries Small countries (top 30 - 40)

Summary of 2017 results Estimated based on survey data Estimated based on MNO data Total Number of trips by country 9.0 million 1.5 million 10.5 million Number of destination countries 24 129 153 Average trips per country 380,000 12,000 69,000

Thank you Ossi Nurmi 15th Global Forum on Tourism Statistics, Cusco, Peru November 2018 26 February 2019 Ossi Nurmi