As political power is biased in favor of the rich even in a democratic system, namely the study of the US by Larry Bartels, will there still be a

As political power is biased in favor of the rich even in a democratic system, namely the study of the US by Larry Bartels, will there still be a difference in democratic versus authoritarian governing performances? And what are the contributing factors behind? Meanwhile, may I know how does the selectorate theory explain political performance with the environment of leadership selection?