You're free to think of this as a redefining of terms, but the first person to make that argument upthread was downvoted to grey. That tends to indicate that I'm not the one redefining a term in a novel way.

But to answer your question, economists refer to "household income" and they don't care if you have a vacation home.

If you look at the origin of this thread, it relates to a single family with multiple homes. If you can't see that a family does not cease to be a family when they purchase a second home, then nothing I can say will convince you. Cheers!