Hopefully I Can say this in a way for everybody to understand.

It is not only the horizontal distance to the target that determines the amount of arrow drop, it is actually how long it takes for your arrow to get there.

Understand that the calculations that i am making would neglect all imperfections, such as friction, floating, or bow error, or LIFT.

Lets say you are shooting at a target that is 10 yds away, and your treestand is 10 yds (30ft) high. The horizontal distance is 10yds, while your actual distance is about 14.1 yds. Lets also say your bow shoots at 250 ft/s.

well if you are shooting from the ground, your arrow is going to take about .12 seconds to hit the target. If your are shooting from your stand it takes your arrow about .17 seconds to hit the target. If you take these numbers; the arrow that was shot from the ground will drop about .68ft or (8in),,, the arrow shot from the stand will drop about .96ft or (11.5in).

But, the farther away your target the less the arrow shot from the stand and the arrow shot from the ground would differ.

So the answer to this question is your arrow will drop more from a stand than it will from the level ground.

BUT AS FOR A SOLLUTION:

The best sollution to this problem as all hunters will tell anybody that asks this question, would not be "Get out your calculator and Dynamics book" It would be "Take your bow out to your stand and practice shooting out of it"