Is Spanking Children an Effective Consequence?

I don't recall ever receiving a spanking as a child. There aren't any specific occasions that spring to memory, but I'm sure it happened one or two times (because my parents weren't against spanking). However, I do clearly recall the instances when my brother received spankings.

In our home, spankings were administered exactly as they were "meant to be": quietly, logically, and with an emphasis on assisting the child in comprehending the nature of the punishment.

I, however, am not in favor of it. My daughter is now thirteen years old, and I've never felt at ease with it. I have friends that spank, and I don't hold that against them in the slightest.