I've found that in general, people tend to give you as much space to your left (right for me) as you give yourself on the right (left). So curb-hugging tends to result in more close passes from people squeezing by. If the lane's wide enough, I'll ride a reasonable distance from the edge of the road, so cars can pass relatively easily. At most, they'll have to cross the central line and pass by driving in the middle of the road. If the road isn't wide enough, I'll ride far enough over to make it clear that they have to overtake me as they would a farm tractor.