I took the expression to mean "household finances" which is how a family run their budget. This is the actual implementation of the school subject "home economics", and this expression is used in English today. How would I say "household finances" in Modern Greek? BTW if this expression isn't used that much today as the Greeks on this post seem to be saying it, why is it being taught to us?
I'm not sure if there's a direct equivalent in English, but I think it refers to the school subject l Οικιακή Οικονομία, which is literally about economic (and other) household matters. I'm not sure if it is still a thing though. I haven't head about for a while. ._.
(That's just an assumption, since the sentence η οικονομία του σπιτιού, exactly as it is, doesn't make that much sense.:P)
So after reading the comments I have come to the conclusion that neither phrases make sense in either language, neither in Greek nor in English.
Who created these translations? Some of them are reeeeally bad.
That said, there could be two possibilities in English:
"The domestic economy"
"Household finances" (no preceding "the")
I think you are misinterpreting the meanin of "housing" see here"
There is a very easy way to always use exactly the right word/phrase for the translations.
Just follow these:
TIPS TO MAKE LEARNING EASIER + HOW TO REPORT A PROBLEM
And check out the Greek Forum here with more links.