Comparison of estimates of the number of visitors to the UK using standard socio-economic indicators, and estimates using Flickr data.

We analyse data for all 28 countries of origin depicted in Fig 1, from 2008 to 2013. (A) Estimates of the average number of visitors per year to the UK, generated by a regression model using the detected number of Flickr users visiting the UK only. (B) Estimates generated using five socio-economic indicators, namely whether the country of origin has English as an official language, the population of the country, the GDP per capita of the country, the distance between the largest city in the country and London, and the stringency of UK visa requirements for citizens of the country. (C) Estimates generated by a combined model, using both Flickr data and the socio-economic indicators. We find that the combined Flickr and socio-economic model significantly outperforms both the Flickr model (F(5,21) = 4.75, p < 0.005) and the socio-economic model (F(1,21) = 14.57, p < 0.005). (D) In the combined model, regression coefficients for Flickr, language and distance are significantly different from 0. Error bars indicate 95% confidence intervals.