I avoid travel during the Christmas and New Year's periods because it is a no-brainer that this sort of rise in rates is going to occur and has for all of my life and probably long before I was alive as well.
The entire world operates on supply vs. demand so we can't really point our fingers at the "evil airlines" and accuse them of doing anything wrong. If one of us owned a business that absolutely boomed in a guaranteed fashion during a particular time of year we too would up the prices. Life is not a charity.
There are other holidays that can increase the price of flights as well but no one of them hits the market quite like Christmas does. I did a little bit of personal research to see what the increase ended up looking like by looking at various travel avenues to and from various locations and the increase seemed to be pretty standard regardless of where you were going.
I included multiple domestic (inside the USA) flights as well as several destinations internationally with one of them being from the USA and another being outside the USA that didn't stop or even travel through it. The results were about the same and it might not surprise you that the largest price increase was on domestic flights that never leave the continental United States.
I used mid-November dates for departure and arrival and also early December dates as well in order to accommodate for Thanksgiving, which is a USA-specific holiday where airlines jack the prices. For the Christmas dates I did a "work weekend" flight of departing on the 23rd and returning on 28th or 29th, which is presumably when most people would need to return to work.
The largest increase was in the continental United States where we saw and increase of nearly 60% in the cost of flights. The lowest increase we saw was a flight that was international, but never went to the USA and never traveled through it. For me I used a flight in Asia as well as a flight to/from Mexico and Central America. In Mexico / Central America the flight price increased around 20% with multiple destinations but the not-so-surprising this was that in Asia, the price went up so little that it could just be a coincidence and doesn't really have anything to do with Christmas. The increase in Asia was normally below 10%. I played with the dates a bit to make sure that it wasn't just normal fluctuations by day of the week.
The international flights that involved beginning or ending in USA were the hardest hit with fare increases, with rates jumping as high as nearly 200% for flights that were departing on the Saturday or Sunday immediately following Christmas day. One of the more surprising things to me was that it was the budget airlines that were the biggest offenders of this, such as Frontier, JetBlue, and Spirit. To me these are all airlines that I avoid at all costs so that wouldn't affect me much but sadly, this makes me feel as though the airlines perhaps know that they can get away with ripping off the poor a lot easier than they can other segments of society.
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Spirit, who I consider to the be the worst airline in the world, at least redecorated a plane or two with non-denominational decorations!
Again, I am not trying to say that they shouldn't do this. If I owned a business and knew I could charge more I would do so as would any other business that had any business sense.
A long time ago my family and I started to not meet on the holidays but that is because we have the luxury of doing so. We all either work remotely or are retired so if we want to meet at a cheaper time such as mid January when flight prices plummet, we have that as an option.
I don't want to say that we were entirely inspired by the "Festivus" episode of Seinfeld that made us do this, but it certainly didn't help.
If people have no choice because of their jobs than to fly during this time then I guess you have to do it! For my family I guess we are too frugal for that and we cut off the holiday get togethers quite some time ago and probably saved thousands of dollars in the meantime.
I'm sure nobody is surprised that airlines are upping the prices during this time of year but this is the first time that I actually went and looked with my own eyes to see what it is all about. It does go up quite a bit and for the price-sensitive, it might be a better idea to just exchange gifts the following or proceeding weekend. I guess it all depends on how much emphasis your family puts on the 25th of December. For mine, it has become and arbitrary day and we don't even put out a tree anymore. It was an easy decision for us to make.