Page 151 - Special Topic Session (STS) - Volume 4
P. 151

STS571 Ossi Nurmi et al.
                1.     The data from two different operators are highly correlated. The
                       monthly seasonality is nearly identical and in line with outbound
                       tourism based on Finnish Travel –survey.

                2.     Depending  on  country  of  destination,  the  top-down  approach
                       dramatically  over-  or  underestimates  the  total  number  of

                       outbound  tourism  trips to  that  country.  There  are  many  known
                       sources  of  bias  in  mobile  data:  non-tourism  trips,  border  noise,
                       devices switched off, multiple devices, transit corridors, conceptual
                       differences etc.
                3.     Mobile positioning data provides a better estimate on the monthly
                       seasonality of outbound tourism. The monthly estimates of Finnish
                       Travel -survey are affected by randomness due to small sample
                       size.


            5.  Results: Country specific estimation
                How should the survey data be enriched or recalibrated using MNO data
            in order to improve the accuracy? The proposed method for recalibrating the
            outbound trips data has to provide at least the following estimations:
                1.     Annual number of all outbound trips
                2.     Monthly seasonality of outbound trips to each country
                3.     Annual number of outbound trips to each country
                4.     Year-on-year change in the number of outbound trips
                For annual number of outbound tourism trips (1.) the Finnish Travel-survey
            provides a solid estimate as shown earlier. For monthly seasonality (2.) the
            MNO data is more robust as it is not affected by survey randomness. For trips
            to  each  country  (3.),  the  best  data  source  depends  on  the  country  of
            destination. At present, it’s not possible to evaluate the year-on-year change
            as MNO data is available only for 2017.





















                Figure 6 – 95 % confidence intervals for top 30 destination countries (excluding top 3)



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