Ryanair job creation figures of 1,000 jobs for every 1 million passengers is taken directly from research produced by Airports Council International (ACI), which is the representative body for Europe's largest airports groups including Aeroports de Paris, AENA Spain, BAA UK, DAA Ireland and Fraport.
This research report (see below) confirms that 950 - 1,000 "on-site" airport jobs are created for every 1 million passengers at international airport.

