Over the last month, newspapers and film Web sites have proclaimed “Avatar” the highest-grossing film in American history. It isn’t true, at least not in any meaningful sense. It is a figment of flawed statistics, and it’s a nice example of how economic numbers are often misunderstood.

Moviegoers in this country have now spent about $700 million on tickets to “Avatar.” That is the basis for the claim that “Avatar” is the top-grossing movie. No. 2 on the all-time list is “Titanic,” which brought in about $600 million. “Avatar” surpassed “Titanic” in late January.

The problem with these numbers is that they aren’t adjusted for inflation.When you don’t adjust statistics for inflation, you end up with a lot of meaningless comparisons: Almost everything is more expensive than it’s ever been! People are earning vastly more than they ever have! The most successful movies ever are being made right now!

Take a moment to think about that last statement, though. Before World War II, the average American went to the movies about once a week. Today — when people can entertain themselves with cable television, rented movies, the Web and so much more — the average American goes to the movies less than once a month. So it’s hard to argue that this is the golden age of moviegoing, and it’s hard to imagine that 45 of the 50 most successful films of all time have really been made in the last 20 years.

The reason you hear that today’s movies are so successful is inflation. Over time, the value of a currency tends to shrink. And the numbers that appear on price tags and on paychecks rise. By themselves, however, these numbers are just numbers; they don’t have any larger meaning. They matter only insofar as they describe how expensive something really is — how long someone had to work to afford it, for example, or what someone had to sell. Adjusting for inflation puts those numbers on a price tag or a paycheck into context.

When you adjust movie grosses for inflation, as Box Office Mojo does, you see that “Gone With the Wind” remains the top-grossing movie of all time, with $1.5 billion in box-office sales (using today’s dollars). When was “Gone With the Wind” released? 1939, the golden age of moviegoing. “Star Wars,” which came out in 1977, is No. 2. Avatar is No. 15.

I suppose that “Avatar” gets called No. 1 for several reasons. Some people are trying to promote the film. (“Gone With the Wind” doesn’t have a lot of Hollywood publicists to make its case today.) Some people find inflation adjustments complicated. (And they can be. There are numerous ways to adjust for inflation, but almost any of them is better than not doing so.) And others find the notion of the “best ever” storyline too good to pass up. But it just isn’t correct.

One other detail: “Avatar” would be closer to the top spot in a ranking ofworldwide grosses, as opposed to ticket sales only in this country. This worldwide list, also from Box Office Mojo, is not adjusted for inflation, but you can do the math yourself. Based on these numbers, “Titanic” is slightly ahead of “Avatar.” “Star Wars” may or may not be, depending on how much of its gross came in 1977 and how much came in later years. I also wonder whether there is good data about the worldwide grosses for “Gone With the Wind” and other old movies.