The cost of going to the movies is going the way of other food and gas prices -- up, up, up.

The AMC theater chain that owns Loews in the past week raised the price of an adult ticket by $1 to $10, and tacked on a 25-cent increase in popcorn prices, too.

At least part of the blame, some economists say, may be linked to the green movement. Corn prices have been rising as more is used to produce the fuel alternative ethanol. That has created a double-whammy for theaters, which generate as much as 45 percent of their sales from popcorn and other concessions, which are used to subsidize their ticket costs.

Economist Richard Gil, of the University of California at Santa Cruz, predicts that the price of movie tickets could jump as much as 30 percent this year as rising corn costs trickle down to popcorn and ultimately movie tickets.

Average ticket prices already have risen 3 percent since the beginning of the year, on top of a 5-percent increase last year. And in some cities, ticket prices have jumped above $10.

Movie-goers don't appear to be deterred too much yet by the higher ticket and concession prices -- domestic ticket sales are off about 4 percent and attendance is down 7 percent so far this year, according to industry tracker Media By Numbers LLC. But those figures don't fully account for last week's blockbuster opening of the latest "Indiana Jones'' sequel, or this week's arrival of the ballyhooed "Sex and the City'' movie.

Still, there are signs that the overall cost of going to see movies is starting to weigh on fans.

Alexis Sinkow, 20, of Philadelphia, said she would have been willing to pay $20 to see "Sex and the City," which attracted throngs of women to the SouthSide Works Cinema Thursday night to purchase tickets to this weekend's opening -- a theater manager said he had never seen such a surge in the sale of advance tickets.

But the rising price of movie tickets has forced her to cut back on the other shows she sees, Ms. Sinkow said. And she and her friends pass up on the food and drink.

"Five dollars for a soda is just ridiculous," said Malory Dobson, 20, of Punxsutawney.

"Why do you think we carry these big purses?" asked her twin sister, Malisa Dobson.

To Nick St. James, who sees a couple of movies a month because he still considers them entertainment bargains, it isn't the price of the tickets that bothers him as much as the cost of gas for getting to the theater.

The result, said the retired 64-year-old analyst from Mount Washington, is that he's willing to pay a little more to see a movie near his home, such as at the SouthSide Works. And as far as the popcorn, Mr. St. James said, he couldn't imagine seeing a movie without it.

A spokeswoman for Kansas City-based AMC said the recent increase was part of a restructuring of ticket prices to simplify the chain's pricing system, and really wasn't related to popcorn prices. Now, all movies during off-times are $5 and all movies during peak times are $10, she said, adding the chain is constantly reevaluating its ticket prices.

At the SouthSide Works Cinema, ticket prices so far have remained at $8.75 for a full-price adult ticket. "There's a certain limit people will pay for things, and we don't want to cross that line," said David Huffman, director of marketing and concessions at the theater. "We haven't put any of the costs on the consumer yet."

While concessions are a big part of what theaters pull in, it's not easy for them to continually raise popcorn and other prices to make more money to hold the line on ticket costs. That's because their costs are rising, too, as suppliers pass on a range of higher prices, from fuel and corn to coconut oil used to pop the corn and paper pulp used for packaging, said Larry Etter, chairman of the National Association of Concessionaires.

Another way theaters try to offset their higher costs is by increasing the number of ads that appear on the big screens before the film starts. Many consumers do not mind these ads, said Mr. Huffman.

Mr. Huffman said theaters also could charge higher ticket prices for an opening night, when a movie is in high demand, and drop them afterward. In the same vein, it could lower prices for matinees.

In the end, theaters try to be flexible to cater to their audience -- and at the same time, stay in business, Mr. Huffman said.