As thousands of TV and film writers marched along Hollywood Boulevard in the third week of their strike, film officials put a price tag on the potential economic toll of the walkout. Los Angeles’ economy will lose more than $20 million a day in direct production spending if the writers strike extends into next month, according to FilmL.A. Inc., the nonprofit group that handles film permits and promotes the industry, the Los Angeles Times reports.

“If the strike continues it’s going to have a huge impact on the local economy and middle-class jobs,” FilmL.A. President Steve MacDonald said Tuesday.

Writers walked out more than two weeks ago in a dispute with major studios over pay for work that is distributed via the Internet, video iPods, cellphones and other new media. Writers and major studios are set to resume talks Monday, although the guild has vowed to continue striking until a deal is finalized.

On Hollywood Boulevard on Tuesday afternoon, striking writers were joined by members of such unions as the Screen Actors Guild, Teamsters and Service Employees International Union. The solidarity march drew 4,000 people, according to the Writers Guild of America.

The 1 1/2 -hour rally, which moved along the historic stretch of the boulevard, kicked off with an appearance by R & B; singer Alicia Keys. “I’m here in support of this cause,” she said amid deafening cheers. “I want you to know I am a writer, too.”

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