rollergator said:
I think the *answer* (maybe just more questions, LOL) comes from the possibility/likelihood that the *fewer* people who stay later just MIGHT be those who keep your cap-ex nice and high.
You know how we talk about the balance and guesswork to the whole pricing thing and in turn talk about how the parks themselves have an advantage over us armchair CEO's because they have access to the numbers?
Well this is one place that I imagine no guesswork is involved. They know how much money is being spent - on both sides of the fence.
My guess is that even if the the remaining number of guests are the types who spend at the end of the day, that it's still not enough to make up for the money saved.
Just think of one thing - like employee wages alone. How many people are working in the park for those last two hours? Tons!
And I often wonder how much the cost of running the park increase once the place lights up. That's a lot of electricity! 
With that said, let me play hypocrite.
Do I enjoy the parks at night? Of course!
Do I often stay until close? Not so much anymore.
Do I stay until after dark? Ehhh, sometimes.
Does it make business sense to cut hours at the end of the day? I can see how it could and apparently so can the parks.
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