Just how influential are the movies in transforming audiences into potential tourists?

The subject is hotly debated, but tends to err on the side of let's-throw-caution-to-the-wind, according to some sceptics.

A 2007 Oxford Economics study supposedly found that Crocodile Dundee and other movies led to a 20 per cent boost in American visitors to Australia in 1980s. The same study supposedly showed that Lord of the Rings led to a 17 per cent increase in visitor spending in New Zealand.

Former Screen Council head Tim Thorpe finds that difficult to believe. These days Thorpe is a consultant and has written several articles for industry website ScreenHub about the hype that often accompanies discussion of the wider economic benefits of the film industry.

"Film tourism (ie tourism influenced by film production and exhibition) is an established fact, but the actual facts seem hard to establish," he recently wrote.

"I was reminded of this at the recent Cineposium conference in Wellington ... Three speakers took the stage but the actual amount of qualitative data presented was not strong."

Thorpe has difficulty correlating the Oxford study with a survey carried out by Tourism New Zealand which showed that in just one year, 112,000 people cited Lord of the Rings as one of the reasons they decided to come to New Zealand.

Just over 10,000 said the movie was their main reason for visiting.

That might sound impressive but in fact it's only 0.3 per cent of all visitors for that year, he notes.

Thorpe doesn't dispute that Lord of the Rings has clearly been a boon for towns like Matamata, which was largely ignored by tourists before Hobbiton came along.

However, it is sometimes forgotten that Lord of the Rings actually pre-dated the Large Budget scheme, he says.

And given that taxpayers forked out a large fortune for that particular project, you would certainly hope that the spin-offs were considerable, he chuckles.

Of the movies made since then, very few are likely to have had significant spin-offs for tourism, he believes.

"How much of the money that has been spent on Power Rangers, and Last Samurai and King Kong has gone into tourism? I'd say next to nil. Sure, there will be some out of The Hobbit, but it will be incremental on what was gained from Lord of the Rings."

Los Angeles-based entertainment lawyer Jonathan Handel isn't sure that he agrees. Thorpe may be ignoring how many Americans are still not even aware that New Zealand exists, he says.

Even if it's only a reminder to those who have already seen Lord of the Rings, it may well galvanise a few to finally book a ticket, he believes.

"The publicity that New Zealand will get, especially the videos on DVDs, does have real value. There's no doubt about that. But the other thing with any kind of advertising promotion is reach and also frequency, and how often is the message repeated," he suggests.

"I wouldn't discount the value five or eight years after Lord of the Rings of having additional material, but whether that's $25 million worth, I leave to more experienced people to debate."

The Ministry of Economic Development has confirmed that an independent review of the Large Budget scheme due to be carried out in 2012 will examine tourism benefits.

A 2005 review noted plenty of anecdotal evidence from happy tourist operators.

It noted that around 56,000 copies had been sold each year of the guide book to the Lord of the Rings locations, and that Hobbiton in Matamata was still getting around 44,000 visitors a year.