In Search of Party Cohesion: The Emergence of Anti-Defection Legislation in Israel and India

Abstract

Although there is a large body of comparative literature on party discipline and cohesion in legislatures, little attention has been paid to the examining the causes that lead to the establishment of formal rules that regulate individual deputies’ ability to defect from their party. This is an important lacuna in the literature that needs to be addressed for several of reasons. First, several parliamentary systems around the world have adopted such rules. Second, anti-defection laws plausibly strengthen the institutionalization of legislative party systems. Third, such laws have a direct institutional effect on the dynamics of government stability, which has been hitherto ignored by the coalition theoretic literature.

The paper starts with a theoretical model that specifies the conditions that shape the demand for and supply of defectors. We assume a 2-player model where demand for defectors comes from the opposition and defectors are supplied by the governing party, or governing coalition of parties. Demand for defectors is specified as a positive function of the size and the ideological coherence of the opposition: the larger and ideologically more connected the opposition, the stronger its demand to attract defectors from the government in order to form an alternative coalition that can take office. On the supply side, defection is specified as a positive function of the size of the governing majority: the larger the number of legislators who do not make a marginal contribution to the winning, i.e. majority, status of the governing coalition, the greater the number of potential defectors who cannot realize the full benefit of being part of the status quo majority. Thus, large governing majorities, with a surplus of legislators, as well as tightly balanced bipolar legislatures provide equally favorable conditions for defections. This expectation should, in turn, prompt party leaders to seek legislation that would increase the exit costs for individual members of their caucuses.

Using the model, we provide an explanation for the introduction of anti-defection legislation in the Israeli Knesset in 1991 and the Indian Lok Sabha in 1985. While the Israeli legislation sought to reign in demand for defectors in a very tightly balanced Knesset, the Indian legislation was a response to an anticipated large-scale exodus of deputies from the majority Congress Party. In both cases, the legislation was successful in keeping defectors at bay and keeping the governing majority together. We rely both on primary sources (Lok Sabha parliamentary debates and Knesset committee and parliamentary proceedings) as well as secondary analyses to reconstruct the process of the passage of these laws.