Log rolling is a tactic used by legislators to tack on favored bills to proposed legislation without conducting serious debate on its issues. It may be accomplished by a legislator agreeing to vote on another legislator's bill in exchange for the other legislator's vote on his/her own favored bill. A concession may be made to another party on a less important topic in exchange for that other party's support on a more vital issue. Another tactic is to include several sub-bills in one bill when passage of them individually is not possible.
The term is also used for similar activities in academics, when one author quotes another and vice versa in order to drive up reference counts.