Parties value unity, yet, members of parliament face competing demands, giving them incentives to deviate from the party. For members of the European Parliament (MEPs), these competing demands are national party and European party group pressures. Here, we look at how MEPs respond to those...

Literature on international organizations points to several potential sources of bargaining power: voice, exit, and exclusion. In some circumstances, a member state may be able to effectively voice objections to a change to an organization's institutions. In others, it may threaten to leave the...