When movie ticket sales in Buenos Aires dropped 40 percent, forcing some cinemas to close, experts blamed just about everything: the government's austerity program, bad weather, the growing popularity of VCRs, outdoor sports and competition from television.

A suggestion for a ban on television movies on weekends got no-where.After months of hand-wringing, the theater operators hit upon an idea.

The operators and the government-run National Cinema Institute, which promotes Argentine filmmaking with subsidies earned on a 10 percent tax on cinema sales, declared Oct. 30 "National Film Day," commemorating elections that led to a return to democracy, and an end of censorship, in 1983.

Everybody who went to a movie on National Film Day got four free tickets to go to any movie theater in Buenos Aires, providing they went on the same day.

The response was overwhelming. Long lines formed throughout the capital, blocking traffic.

The success of Film Day was undeniable.

Without counting the four giveaways, Buenos Aires movie operators that Sunday sold nearly as many tickets - 42,000 - as they did in a four-day, Thursday-Sunday period Oct. 20-23, when 53,117 were sold.

The conclusion was inescapable.

People had stopped going to movies because the ticket price, at 25 australes ($1.65) - an amount that for years had been automatically indexed to keep pace with inflation - was simply too high for the average Argentine, whose income ranges between $200 and $300 a month.

A drop in price or a promotion would obviously lead to a resurgence in sales.

A day after National Film Day, movie houses acting together slashed the price to 15 australes ($1), except for a handful of theaters in wealthier neighborhoods that were authorized to charge 20 australes ($1.33).

"We are encouraged by the results," said Julio Raffo, secretary of Argentina's Chamber of Cinematographic Industry, in a telephone interview.

"We are not only interested in making the product cheaper but also in regaining a film audience we have lost through the years. We want to recreate the movie-going habit."