My child has immense respect for me even though I don't hit him. I think the respect is based on the fact that I am four times his size, he depends on me for food, I have answers to his questions, and I am his parent. I don't think I need to hit him in order to get across the fact that I'm in charge because it's so obvious. That's why hitting a child is such a mistake: it takes the message of who's in charge over the top.
What spanking does give a child is low self esteem. I bet you know someone with low self esteem who also was spanked as a child.