@olamundo My understanding is that we hav efewer methods to detect stars farther away from their host star. Therefore I might expect that there will be a bias in detecting fewer of them.
I am no astrophysicist though. So naturally I am not the best person to answer this.
@robryk
Yea the wobble method, which is closely related to the doppler shift method in principle, works well too. One issue with both these methods, as I understand it, is they are more effective picking up more subtle effects (like planets far away) when there are fewer planets orbiting the star. Otherwise the pulls tend to average out and you get less wobble.
@olamundo