That's complete crap.
First of all, the majority of the tax is already included in the tickets. The yearly tax is based on net earnings, not revenue. A producer has a lot to gain from giving higher figures. Better deals for future projects including video rights, satellite rights, music rights, distribution rights. The whole works. It even gets shadier when the production company happens to be owned by the lead actor.
A distributor on the other hand has first hand data, but even they are inclined to give lower figures because they have to give half of the ticket sales to the producer.
So no figures are a 100% correct, the true amount is usually somewhere in the middle but the distributor amount is usually considered when comparing different films because they are consistent while every production house works differently but they all inflate their figures.
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