No matter how many times I tell people that airfare prices can't be predicted, this question always comes up in some form or another, so I've decided to write an article that I can start referencing people to.
For the record, asking 'Is this a good price?' is essentially the same question, just worded differently. They both depend on what future airfare prices will be.
The truth is, even the airlines themselves don't know what fares they'll be cutting. They plan on selling X number of seats for X number of dollars, and if that doesn't happen, they may find it necessary to drop the price to fill those seats. Or it can be a result of a competitor dropping their price on a certain route, which is an unpredictable event.
The demand for those seats can be influenced by *so* many variables, from the overall health of the economy, to whether or not people feel like flying there this year, to when or where the next flu epidemic hits.
The prices are reactionary to events beyond anyone's control, which is what makes them unpredictable, by you, me, or anyone else.
That being said, there are certain generalities that can apply, depending on the destination. Just keep in mind these are simply things I've learned from obsessively watching airfares, and there's never any guarantee of anything in the world of travel prices.