The answer to my headline question as of this morning? Only Alaska, Virgin America and Frontier have not raised ticket prices to take advantage of the political standoff in Washington that has denied funding to much of the Federal Aviation Administration. And of the three, only Frontier serves PHL. The FAA's air-traffic control system appears to be functioning normally today, with the airport's PHL.org Web site reporting mostly on-time operations. Here is the story of how all the other airlines immediately raised ticket prices when the lack of an FAA funding bill meant the agency no longer had the authority to collect the taxes that are part of every ticket. What FAA can't collect in aviation taxes is noted in this story.
What's the reason for the lack of funding for the FAA? Although much criticized, the agency usually has had bipartisan support. This dispute is over $16.5 million for subsidized air service for rural areas, including some airports in Pennsylvania. House Republicans intent on shrinking government down to the point it can be drowned in a bathtub believe that stopping that kind of cost is important enough to hold up the entire FAA budget. More background on the dispute and more information on what the ticket-tax suspension means can be found in the links above.