Policy Engagements and Blogs

The Battle for Bihar: Understanding the Upcoming 2015 Election

September 29, 2015


In the next six weeks, Bihar will elect 243 members to its state assembly. The Bharatiya Janata Party (BJP) looks to continue its momentum in Bihar from a sweeping victory in the 2014 national election, while once bitter enemies, Janata Dal United (JD(U)) and Rashtriya Janata Dal (RJD), have banded together to try to stop BJP’s ascent.

In this piece, we summarize the changes that have taken place in Bihar since 2010, and use data from the Election Commission of India (ECI) to provide a perspective on broad trends from the 2010 and 2014 elections. We pay particular attention to the relevance of the “caste arithmetic” of wooing different caste groups for electoral outcomes in Bihar.

Bihar since 2010

In 2010, the National Democratic Alliance (NDA) in Bihar, comprised of BJP and JD(U), virtually swept the state election, winning 206 of the 243 seats. Since then, Bihar has seen a spectacular reconfiguration of party alliances.

The 2014 election saw BJP and JD(U) parting ways over the selection of Narendra Modi as prime ministerial candidate, with BJP picking new partners and JD(U) running alone. The BJP alliance won 31 of 40 constituencies, with the JD(U) winning just two. Then chief minister (CM) of Bihar, Nitish Kumar of JD(U), resigned after taking responsibility for his party’s poor show. In his stead, JD(U) appointed Jitan Ram Manjhi, a leader for vulnerable “Mahadalits”, as the CM. However, when Nitish Kumar sought to return as CM, Manjhi was forced to leave his post.

Since then, a disaffected Manjhi has formed his own party, the Hindustani Awam Morcha (HAM), joining hands with BJP in NDA. The Lok Janshakti Party (LJP), previously breaking with NDA in 2002 while calling BJP a communal party, has come back to NDA. Fearing the ascent of BJP, once opponents, JD(U) and RJD led by Nitish Kumar and Lalu Prasad Yadav, respectively, have formed a pre-electoral coalition with the Congress Party to fight against the BJP-led NDA in this election.

The 2014 National Election: The NDA in a Dominant Position

Like much of India, Bihar strongly supported BJP (and NDA) in the 2014 national election. Although the election was contested in larger parliamentary constituencies in 2014, the ECI provides a vote breakdown by smaller state assembly constituencies (ACs) of the 2014 polls. The AC-wise analysis provides a benchmark of the popularity of each party just one year ago.

In 2014, NDA, comprised of BJP, LJP and Rastriya Lok Samta Party (RLSP), was the leading vote-getter in 172 out of 243 ACs in Bihar. Of these 172 ACs, RLSP won 17, LJP won 34, and BJP won 121 ACs (almost a simple majority). By contrast, RJD, JD(U), and Congress won 32, 18, and 14 ACs, respectively. To understand party performance, we calculate the strike rate for selected parties in 2014, i.e., the percentage of ACs contested by the party in which the party was the top vote-getter.



The strike rates of each of the major parties challenging NDA fell below 20% in 2014, with RJD and Congress displaying strike rates of 19.5% and 19.2%, respectively, and JD(U) winning a paltry 7.8% of the ACs in which it contested. By contrast, the parties forming NDA in 2014 (all of which have returned under the NDA banner) had strike rates of at least 65%, with BJP and LJP displaying strike rates of 66.5% and 79.1%, respectively, and RLSP winning a nearly perfect 94.4% of the constituencies in which it contested. Importantly, the strike rates of BJP’s coalition partners are even higher than BJP, showing their indispensability to NDA.

How Much Does Vote-Splitting Matter?

It has been argued that in 2014 NDA benefitted significantly from vote-splitting between JD(U), who contested the election alone, and the coalition of RJD and Congress (UPA). That is, in most constituencies both JD(U) and one of RJD or Congress each fielded a candidate. Perhaps NDA would have fared much worse in Bihar if voters didn’t distribute their votes across these two NDA-opposing candidates. In order to test this hypothesis, we coded landslide victories in 2014, where the winning party had a larger vote share than the next two parties combined. The NDA won 79 constituencies by a landslide in 2014, clustered mostly in western Bihar, with the BJP getting over half of its victories (61) by landslide. In other words, even if the coalition of RJD, JD(U), and Congress were allowed to field two candidates and take their combined vote share, they still would have lost to NDA in 79 constituencies in 2014. By contrast, JD(U), RJD, and Congress recorded 5,5, and 6 landslide victories, respectively, largely clustered in the Muslim-heavy northeastern part of the state.



If NDA can continue its electoral dominance in a significant share of its 79 landslide constituencies, it will be tough to beat. NDA’s success in 2014 is not a simple case of vote-splitting, and its opposition must make significant inroads into NDA’s electoral base to win the election.

Comparing 2010 and 2014: Wither Caste-Party Outcomes?

When we compare the electoral results in 2010 to the AC-level data in 2014, the immense amount of electoral volatility in Bihar becomes apparent. Only 30.9% of ACs were won by the same party in 2010 and 2014. The standard caste narrative posits that there are “dominant castes” at the constituency level who act as kingmakers. While these castes may switch partisan allegiances, there are purported to be strong caste-partisan affinities such as Yadav support for RJD and upper caste support for BJP. Empirically, this implies that parties like RJD and BJP should consistently stand for election and win in the same sets of constituencies, thereby displaying significant incumbency advantages.

Yet, we find a different picture. RJD increased its tally of ACs from 22 in 2010 to 32 in 2014, but it only held on to 7 of the 22 ACs it had won in 2010. By contrast, 23 of the ACs the RJD won in 2014 were actually won by NDA in 2010. BJP had a strike rate of over 50% in constituencies where RJD had won in 2010, significantly higher than RJD’s strike rate in the same constituencies. In 2014, BJP had a strike rate of 70.1% in constituencies it won in 2010, but this was not significantly higher than its overall strike rate of 66.5%. In short, constituencies won by RJD and BJP in 2010 did not carry a discernible caste advantage for re-election.



While caste matters a lot to voters, it may not translate neatly into electoral outcomes. Although voters may prefer to vote for someone of their own caste, many parties select candidates from the same dominant caste group at the constituency level, thereby splitting the caste vote. This may be one reason the BJP has selected many Yadav candidates in the upcoming election. Second, Bihar’s electorate is young, with 56% of voters under the age of 40. This is a population that is less likely to be beholden to traditional caste boundaries and more focused on generating economic opportunities. Bihar exhibits significant electoral volatility, while caste is static. Electoral outcomes are, thus, more likely driven by variable issues such as economic and development concerns.


Our data suggests that NDA is in a stronger position going into the 2015 Bihar election. However, three additional factors could well turn this around. One, it is important to remember that the electorate can shift quickly. Support for parties often swings heavily during a campaign because voters receive a lot of information about parties and candidates at once. Two, national parties like BJP may be more appealing in a national election, but this appeal may not translate as cleanly to the state level. Three, people in Bihar seem satisfied with Nitish Kumar’s tenure as chief minister, and NDA will have to make a convincing argument that it can govern better than him. At the same time, our analysis suggests that the coalition of JD(U), RJD, and Congress will have to do more than banking on the caste vote in order to win the election.

There are two additional “joker-in-the pack” variables. While in most cases this is primarily a contest between the two alliances, the presence of third party candidates (whether from the Left alliance, the Samajwadi Party or Asaduddin Owaisi’s All India Majlis-e-Ittehad-ul Muslimeen (AIMIM)), could well determine close contests between the two alliances. And young voters of Bihar are likely the pivotal group in this election. Who gets their vote, is likely to win Bihar.


We thank Devesh Kapur for helpful comments in writing this piece.

We have furnished a dataset & labels  collated from publicly available ECI data, which was used for the analysis in this piece. All data errors are our own.