Binary thinking

The intuition that a two-party system is a natural consequence of first-past-the-post geographical voting is common, both among political observers in India and political scientists. Among the latter, it is codified as 8220;Duverger8217;s Law8221;, which like most 8220;laws8221; in social science, is an occasionally-observed regularity. Emerging from the assumption that nobody wants to 8220;waste8221; their vote by voting for a party unlikely to win, it appears to hold in most constituencies across India.

In a recent paper, the political scientists Pradeep Chibber and Geetha Murali of the University of California check this intuition and discover that it actually fails about a third of the time. In a large number of constituencies across the country, more than three parties are competitive at any given time. They provide an explanation for this, arising from the simple assumption that voters care about both state and national-level politics, and thus might be willing to vote for national parties even if they are not directly likely to form a state government. Their assumptions, their three 8220;testable hypotheses8221;, and how they check them are extracted alongside.

The authors then consider what their analysis implies for certain Indian states. In Tamil Nadu, for instance, there are several regional parties: they show that within most assembly constituencies, however, at most two are competitive at each time. This fits in with prediction c. In Bihar and UP, however, almost all constituencies have been three-way contests historically: this is not entirely due to ethnic politics, say the authors, because it predates the massive ethnic mobilisation of the 1990s. Since UP in particular has always had more than two national parties, or combinations of national and regional parties competing at the state level, this fits in with prediction a.

Finally, they say several states saw a 8220;spike8221; in the number of locally competitive parties. Andhra Pradesh pre-NTR and Tamil Nadu pre-MGR are two such. They believe that this shows that fragmentation creates 8220;space8221; at the assembly-election level for 8220;political entrepreneurs8221; that can build new coalitions, such as NTR. While they do not state it, it is likely that they believe that Mayawati8217;s success in UP reflects that possibility.