It might be unethical to lie to your kid about Santa Claus... but at the same time, with all of the bad in the world; There is nothing that can go wrong by telling them that there is a being that indiscriminately gives out gifts and toys to all the good little boys and girls, men and women, poor and rich... of all races and backgrounds. That there is a being which treats all humans as humans. Let's be honest, the world sucks. But maybe by believing and spreading the lie you can help make it a little bit better. And that's really what it's all about.
So yeah, I would tell my hypothetical children about Santa Claus. And when doing so, the above is the exact version of the story I would go with. At the same time, if my child were to come up to me and sincerely ask if Santa is real I will admit the lie, congratulate them on being able to use their brain properly and and explain the reasoning behind it.