One of the unfortunate trends in modern written English is avoiding the use of hyphens. Why unfortunate? Used properly, especially in compound modifiers, they can eliminate ambiguity such as that present in the dominant headline on this week's cover of Time magazine.
The headline: The Only Child Myth. What is that supposed to mean? That there's only one child myth? That's the way I read it when I first saw it.
Much improved would have been this: The Only-Child Myth. That's clear, and that's what the author meant.
