The tangled web of travel, part 1: Flights

When you walk into a bookstore, you expect to be able to find all the latest bestsellers. But what if "The Da Vinci Code" were only available at Borders, and Bill Clinton's "My Life" could only be found at Barnes & Noble? That's exactly the situation that's becoming more and more common in the travel industry.

Because suppliers (airlines and hotel chains) rely on third parties (online agencies and travel agents) to sell much of their inventory, customers are at the mercy of the deals struck between those groups. For example, if you book on a particular website, you might pay a higher service fee for a ticket on certain airlines. Or, you might see one hotel chain listed first on a results page, even if its prices are higher. While some degree of "display bias" has existed for decades, rules prohibiting certain types of discrimination in computer reservations systems expired last summer. So before you book a trip, you need to be extra-careful that you're seeing the complete range of possibilities at the lowest prices.

Thomas Petzinger, Jr.'s fascinating history of the airline industry, Hard Landing, describes how American developed the Sabre reservations system used by a vast network of travel agents, and programmed it with "screen science" that would invariably make American flights appear first. Since travel agents booked the first option on their computers more than 50 percent of the time, weighting the display in favor of American flights would increase that airline's bookings. As a result of such practices, the U.S. government began regulating these systems in the early 1980s.

But with the Internet making it easier to compare prices, many of these rules were reversed this year. Now, as Scott McCartney of The Wall Street Journal wrote earlier this month, certain online agencies are preferencing particular airlines. For example, for a trip between Chicago and Minneapolis, CheapTickets.com first displayed a Delta flight that connected in Atlanta, instead of any number of nonstop options. (Because of this bias, Northwest says it won't let CheapTickets.com sell its flights at all.)

There are a few things you can do to avoid the pitfalls of paying too much for an inconvenient trip. First, know which airlines fly your route. (Check out Smarter Living's Flight Schedules.) Then, get a benchmark for what your fare is likely to cost. You could use one of the search engines like SideStep, Mobissimo, or Kayak, or compare fares using several different online agencies. (Only Orbitz promises an "unbiased, comprehensive display" of flight options, but even so, will still add lower surcharges for its preferred airlines.) That way you're mitigating the risk of a potential deal between your airline and the booking site you're searching.

When it comes time to purchase your ticket, I'd recommend buying directly from your airline. You won't pay a service fee, and you'll often get extra frequent flier miles. Plus, you won't have to worry about being directed toward an inconvenient itinerary.

Tomorrow, I'll examine the issue of display bias as it relates to hotels. Profit margins are much higher for hotel rooms than they are for flights. So there's an even greater chance that a particular website is steering you toward its preferred properties. Or, worse, that it simply won't show you the hotel you're looking for.

In short, when you're shopping for travel, be sure to read between the lines. That shouldn't be as hard as solving Dan Brown's murder at the Louvre. But you'll still have to decode the clues to find the right deal for you.