The dynamism of air traffic markets inthe Middle East obscures the persistence of restrictions oninternational competition. But how important are suchrestrictions for passenger traffic? This longer paper by thesame title that this Quick Note is based on uses detaileddata on worldwide passenger aviation to estimate the effectof air transport policy on international air traffic2. Thepolicy variable is a quantitative measure of the commitmentsunder international agreements.The paper analyzes, and forthe first time, not only bilateral agreements, but alsoplurilateral agreements such as the one between Arab states.The analysis finds that more liberal policy is associatedwith greater passenger traffic between countries. Highertraffic levels appear to be driven primarily by largernumbers of city pairs being served, rather than by morepassengers traveling along given routes. To demonstrate thequantitative implication of the estimates, twoliberalization scenarios in the Middle East are evaluated.