Because as a Preposition
In Standard English, the word “because” can be used two ways. One of them is to introduce a clause, as in “Aardvark was late because he was waiting for the repairman to show up.” Used this way, “because” is a subordinating conjunction. The other is to team up with “of” to form what’s called a compound preposition. For example, “Aardvark was late because of heavy traffic.” In the past three or four years, though, a new usage for “because” has been developing.
“Because Evil Emperor Zurg!”
So what is this new way of using the word “because”? Listen to these quotations from an article in Slate this past summer, in which young children were asked to choose their favorite Pixar movie. A five-year-old chose Toy Story 2, quote, “Because Evil Emperor Zurg!” A four-year-old liked Monster Inc. “Because the day care.” A six-year-old chose Monsters University, “because the part where Sully has the big roar and scares all the policemen.”
"Because" as a Preposition
The new usage of “because” treats it as an ordinary preposition, by having it introduce noun phrases instead of clauses or the word “of.” I’ve also heard teenagers say things like, “I’ll do that when school’s out, because more time.”
This construction got a name just last year. In July 2012, two linguists independently decided to call it “because NOUN.” On July 2, Laura Bailey called it this in a post on her linguistlaura blog, and on July 12, Mark Liberman independently did the same in a Language Log post.
But where did this “because NOUN” come from? I have the same suspicion as a few of the commenters on the Language Log post: It has its origins in what I’ll call “because hey” sentences. If you’re old enough, you may remember Jack Handey’s Deep Thoughts, a recurring joke on Saturday Night Live. One of them, written in 1987, went like this: