A complicating factor is that of origin-destination control ("O&D control"). Someone purchasing a ticket from Melbourne to Sydney (as an example) for A$200 is competing with someone else who wants to fly Melbourne to Los Angeles through Sydney on the same flight, and who is willing to pay A$1400. Should the airline prefer the $1400 passenger, or the $200 passenger plus a possible Sydney-Los Angeles passenger willing to pay $1300? Airlines have to make hundreds of thousands of similar pricing decisions daily.
In recognition of the essential national economic role of a healthy aviation system, Congress authorized partial compensation of up to $5 billion in cash subject to review by the U.S. Department of Transportation and up to $10 billion in loan guarantees subject to review by a newly created Air Transportation Stabilization Board (ATSB). The applications to DOT for reimbursements were subjected to rigorous multi-year reviews not only by DOT program personnel but also by the Government Accountability Office[46] and the DOT Inspector General.[47][48]
Where to stay in Zante: Porto Zante, eight villas with five-star facilities, set above a pristine bay of finely raked sand, is kitted out for kids of all ages: there's a playground, mini-golf, and every water-sport under the sun. The sociable Peligoni Club is especially good for toddlers and teens: the crèche is run by qualified nannies and over-13s have their own bar, serving milkshakes and mocktails. Zante Maris Suites, as well as the new Olea All Suite Hotel just next door, are both squarely aimed at adults, with a haute hippie vibe. Kids over 12 are welcome. 

Sifnos owes its foodie reputation to its most famous descendant, Nicholas Tselementes, who wrote the first Greek cookbook in 1910. Forget souvlaki and moussaka: here, chickpea croquettes and stewed capers are taverna staples. The island is peppered with potteries that produce the earthenware casseroles used for revitháda (baked chickpeas) and mastello (lamb with red wine and dill). Traditional dishes are slow-roasted in a wood-fired oven at To Meraki tou Manoli, a local institution on sheltered Vathy bay. (While you’re there, invest in some timeless tableware from Atsonios pottery, in business since 1870.)
Apart from a boat trip to the smouldering crater of Nea Kameni and hot springs at Palia Kameni, there's not much to do but gaze at the mesmerising views from your suite, dangling on the edge of the caldera. The best hotels in Santorini are concentrated in Oia, but the inland village of Pyrgos is up-and-coming. Go for a twilight Bellini at Franco's or a cocktail at newcomer Botargo, with views that will leave you light-headed, followed by dinner at Selene, a pioneer of new Cycladic cuisine.
In 2017, 4.1 billion passengers have been carried by airlines in 41.9 million commercial scheduled flights (an average payload of 98 passengers), for 7.75 trillion passenger kilometres (an average trip of 1890 km) over 45,091 airline routes served globally. In 2016, air transport generated $704.4 billion of revenue in 2016, employed 10.2 million workers, supported 65.5 million jobs and $2.7 trillion of economic activity: 3.6% of the global GDP.[60]
Since airline reservation requests are often made by city-pair (such as "show me flights from Chicago to Düsseldorf"), an airline that can codeshare with another airline for a variety of routes might be able to be listed as indeed offering a Chicago–Düsseldorf flight. The passenger is advised however, that airline no. 1 operates the flight from say Chicago to Amsterdam, and airline no. 2 operates the continuing flight (on a different airplane, sometimes from another terminal) to Düsseldorf. Thus the primary rationale for code sharing is to expand one's service offerings in city-pair terms to increase sales. 
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