What effect does the donation box have?

In Dragon Age II there is a donation box in "Lirene's Fereldan Imports", where you can donate money to the Fereldan refugees.

Does this affect the game in any way?

Solution 1:

Okay, I tried for myself now.

Donating 5 sovereigns = 200 XP (outcome: 0.4 XP per silver)
Donating 1 sovereign = 100 XP (outcome: 1 XP per silver)
Donating 50 silver = 50 XP (outcome: 1 XP per silver)

As one can see, the payout for donating 5 sovereigns is worse than for the other two donations. But as you can only donate once, it may still be worth it, because XP are harder to gain than money.

Solution 2:

Donating 1 sovereign gives you 100 experience. It doesn't currently serve any other purpose.