Personally I think tax cuts and a clear, direct financial advantage to marriage are promising solutions. ..
I've heard this argument long ago, It didn't hold water then, and it doesn't hold water now. If you look it up you will see income taxes have been trending down since the 1950's. Using your logic, problem has already been solved. And this idea you seem to have the reason people don't get married is because is not advantageous tax wise is laughable. Rather easy to prove. Are you married? If so, did taxes ever enter your mind when you did get married? If you're not married is it because you found the love of your life but decided it wasn't worth it because of taxes?