UK International Passenger Survey (IPS).• The IPS is a survey of passengers entering or leaving the UK by air, sea or the Channel Tunnel. This report exclusively used outbound to Western Europe leisure air passenger traffic data from the IPS. Quarterly traffic and price data was taken for the period from 2003 Q2 to 2006 Q2. Traffic figures reflect the estimated number of passengers on a particular airport-pair route during the given quarter, while average price reflects the estimated average price paid (in GBP)