I never thought that something like this could be use in immigration proceedings. However, it would make sense in a country that requires immigrants to be in a certain financial situation.
I'm a US citizen, and a few years ago I was looking into immigrating to Canada. They have specific requirements you must fulfill, such as having a certain amount of assets so you can contribute to the economy of where ever you move to.
I imagine someone immigrating to Canada might have to fill out an affidavit of property!