How do you persuade your parents to get a dog?

I am 13 yrs old and I think I am now responsible enough and old enough to get a dog. I want a teacup pomeranian and please no one say "eww." or "i hate those." or whatever I just want the question answered. My dad says he would consider getting a dog if we moved to the countryside where it has lots of open space to run around since my sister wants a bigger dog, such as a "golden retriever". I live practically in the countryside, well very near it anyway and I just really want a dog!! Do you know how to get one or make your parents consider it??