Veto Players

Veto Player Theory

According to veto player theory, policy stability depends on the number of veto players and the differences among their preferences. Veto player theory distinguishes between institutional and partisan veto players. Institutional veto players are created by constitutional provisions that specify which actors have to give consent to pass a law. Partisan veto players are political actors who enjoy veto power due to political circumstances. For example, the consent of political parties who form the government and have a majority in the parliament are needed in parliamentary systems to enact new legislation. In some instances, other societal actors like interest groups or the military exercise veto power, even though the constitution does not assign a formal role in the lawmaking process to them. To identify the relevant number of veto players, one starts with the constitutional veto players and identifies the potential partisan veto players of which they are composed. For example, the constitution might specify that the laws have to be adopted by the government and the two chambers of a bicameral parliament each acting by simple majority. In other words, there are three institutional veto players. However, one has to take into account that none of the three are individual actors and identify the conditions under which the composite parts of each (e.g., cabinet members or representatives) can exercise their institutional veto power collectively. If political parties are able to discipline their members, the question is how many parties are needed to form the necessary majority in parliament and form the government. In our example, three parties may form the center-left government and a majority in the lower chamber, but one opposition party is needed to reach a majority in the upper chamber. Thus, the number of veto players is four, when we take the political situation into account. In addition, one has to consider the possibility of partisan veto players who are not part of the constitutionally designated set of veto players. The number of veto players in a political system can differ not only across time but also across policy fields. A central bank, for example, might be a veto player in monetary policy but lack veto power in other fields. In our example, the government might rely heavily on the political support of a major trade union, giving them de facto veto power on government policy and thus increasing the count of partisan veto players to five. Finally, an absorption rule applies, because some veto players may be redundant, for example because they have identical policy positions. In our example, the Social Democratic Party in government and the trade union might have exactly the same preferences. Thus, the actual number of veto players is four.

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