When legislators choose not to decide: Abstentions in the European Parliament

Why do legislators choose to vote 'Abstain' instead of 'Yea' or 'Nay'? Is it because they shy away from taking sides when facing competing demands? We address this question by studying roll-call vote data on the 6th European Parliament. In line with our principal-agent approach, we find that Members of the European Parliament are prone to strategically abstain when torn between different positions of their national party, their transnational group, and their country's minister. Abstentions are thus not random but strategic and ignoring them may bias the findings of legislative studies.