This is a bizarrely complex question (it relates to US tax law, so no surprise there). Some households would pay more if married, some would pay more if filing

This is a bizarrely complex question (it relates to US tax law, so no surprise there). Some households would pay more if married, some would pay more if filing separately. See: http://www.taxpolicycenter.org/briefing-book/what-are-marriage-penalties-and-bonuses http://www.taxpolicycenter.org/briefing-book/what-are-marria...