(CNN) -- Thousands of people are opting out of flying for Thanksgiving this year, but passengers who do book plane tickets for the holiday will still see jam-packed flights, the trade group that represents major U.S. airlines said Thursday.
About 23.2 million travelers will fly during a 12-day period surrounding Turkey Day, a 2% drop from last year, according to a forecast by the Air Transport Association of America.
Even though that translates to 37,000 fewer people flying per day over the holiday period, airlines are reducing capacity and limiting the number of seats available for sale to match the lower demand.
"For the busiest holidays, it's always good counsel to book early and book often," said John Heimlich, vice president and chief economist for the association.
"Based on published airline schedules, these cuts are expected to continue through the winter."
The busiest air travel days for the Thanksgiving holiday period are expected to be Sunday, November 27, Monday, November 28, and Friday, November 18, the association said.
The least traveled day is expected to be Thanksgiving Day itself, or November 24, Heimlich said. Experts advise flying on the holiday to avoid the worst crowds at the airport and in the sky.
Heimlich attributed the overall drop in demand for airline seats to high unemployment, a drop in disposable income and high energy prices.
Commenting on the overall state of the airline industry, the association warned that 2011 is shaping up to be worse financially than last year for the airlines, with higher costs outpacing higher revenues. Fuel was the largest driver of expenses, rising 38% for the first nine months of this year.
Razor-thin margins mean carriers are able to keep less than a penny in profit for every dollar of revenue, Heimlich said.
"Given these facts and the commercial situation, it's not surprising that as the year has gone by we've seen a trend toward reduction of seating capacity."