New York >> You booked your summer travel early, only to see the airfare drop.

You have company. The threat of fare increases combined with pent-up demand drove more travelers to book months ahead, according to industry experts.

Advanced bookings were higher in the first three months of the year than they have been in more than two decades, says aviation consultant Robert Herbst. The value of advanced tickets sold at Delta in the first quarter, for example, jumped 37 percent to $4.54 billion.

But while ticket prices on average are higher than a year ago, some select summer fares have dropped from where they were back in March, particularly on those routes with the most competition or fewest bookings.

Before kicking yourself, you should find out if you can recoup the difference. (Warning: In some cases, you’ll still end up kicking yourself. Because you can’t kick the airline.)

Here’s a rundown of refund policies from most of the major airlines:

— Most treat the adjustment to the fare like a change to a reservation and charge a fee. Travelers must factor in that fee when weighing whether to fight for their money back.

— Only three airlines offer refunds on any price drop — Southwest, Alaska and JetBlue.

— AirTran and Virgin America have $75 change fees, so the price drop must be more than that to warrant a refund. At Hawaiian Airlines, the threshold is $100.

— Unfortunately, refunds on the most traveled airlines are more difficult. United, Continental, Delta, US Airways and American all hit you with a $150 change fee — meaning the fare difference would have to be higher than that to make it worthwhile. (OK, now start kicking.)

The likelihood of a swing that big at the height of the summer travel season is pretty slim. Overall, summer fares are expected to be up by about 15 percent compared with last year, according to Bing Travel, as the airlines try to make up for rising fuel costs.

Still, many travelers can benefit from prices going down. Some of the most dramatic examples: Say you booked a flight from Phoenix to Philadelphia leaving on Saturday, July 16, and returning the following Friday on US Airways. A coach class ticket cost $675 in early spring. If you booked Wednesday, it cost $497. For the same travel dates, a trip from Denver to Las Vegas on Southwest Airlines was recently as high as $269. On Wednesday, the price was $165.

Not many travelers, however, bother to check if the fare has dropped after they buy their ticket. A site called Yapta.com allows fliers to register their flight information and receive alerts when fares fall after they book.

If you think you’re eligible for a refund, bear in mind that your airline won’t give you money back for a ticket purchased on Expedia, Orbitz or other outside travel sites. Those sites have their own price match guarantees, but they’re harder to snag.

You need to find a better price online within 24 hours of booking to get money back from Expedia. And another traveler would have to book the same flight for a lower price on Orbitz in order for you to get a check in the mail. That applies any time before your flight takes off.

Also, on most airlines your refund comes as a voucher good for future travel instead of cash. Most vouchers expire within a year. And you won’t even get that if you try to change your itinerary. No changes to destination or airports are allowed.

Of course, you can avoid all this if you land a good fare in the first place. That may be easier said than done, but there are some methods to ensure you don’t "buy high" next time you fly:

Signing up for alerts from sites like Travelzoo and Airfarewatchdog.com will let you see sales and promotions that aren’t otherwise advertised. Kayak.com offers a fare-tracking system that allows potential fliers to monitor the best time to buy. Another method? An application called "Invisible Hand" will scan other websites while you’re booking and let you know if it finds a better deal — and where to find it.