In Seeing things at Disney before they got rid of Eisner, Art De Vany shares a piece he wrote after Disney’s Treasure Planet failed to meet forecasts:
Where Disney went wrong is in having too much faith in their financial analysts. No one knows what a movie will gross. My research (Hollywood Economics: Chaos in the Film Industry) shows (and every movie fan knows) that motion picture revenues are not forecastable; the forecast error is infinite. There is no correlation between opening revenues and total revenues for any movies that are successful. Opening revenue is only a good predictor of total revenue for movies that die in their second or third week. All successful Disney movies (most of the animated ones are) enjoy long runs so that opening revenues become a small portion of their total revenue. And, all successful movies reach a point (about four or five weeks into the run) where they separate rapidly from the pack. This bifurcation point in the mapping is a signature of chaos in the non-linear dynamics of motion picture revenues.Given how little information is contained in a movie’s opening, the weight studios place on it is troubling, particularly at Disney which is a studio where film revenues depend on long runs.
(Emphasis mine.)