We identify the conditions under which voters can induce political parties to collect information and to select policies which are optimal from the representative voter’s point of view. We show that when parties are office motivated the voting rule should encourage parties to collect information. Voting rules that focus on the opposition party sometimes dominate voting rules that focus on the incumbent party. When parties are policy motivated, they also have to be motivated to select good policies. Generally, it is easier to stimulate policy motivated parties than office motivated parties to collect information. However, in contrast to office motivated parties, policy motivated parties will sometimes select policies that conflict with the representative voter’s interest.