Modi Wave or Rising Rahul? This Vote Share to Seat Conversion Assessment Makes Gujarat & Himachal Picture Very Clear

Gujarat Himachal BJP Congress
  • 699

Temperature has gone up this winter as state assembly elections are around the corner in Himachal Pradesh and Gujarat. The two states are quite similar in respect of contest, with no formidable third front, it’s a BJP vs Congress battle. As the fight is intense and clamor is high, I give myself an opportunity to come up with my own analysis. The methodology I have applied is vote share to seat conversion. This method is highly plausible here because it is a direct contest between the two-major political parties.

I forecast the vote share for this election based on Modi wave (increase/decrease of vote percentage for the parties in the 2014 general election as compared to 2009) and other prevailing social-economic factors. This predicted vote share is multiplied with the average of the conversion ratio to get the projected seat share. Data on election outcomes like vote share, number of seats are taken from the Election Commission of India and Population data of Gujarat from Census 2011.

Himachal Pradesh:

There have been six assembly elections in Himachal since 1990 to 2012. The analysis has been restricted to 1990 in the past as, the BJP, which was formed in 1980 became a national force in the 1989 general election and a significant contender thereafter. There are two clear patterns in seat to vote share ratios. First, when both the parties hover around 40% vote share then the ratio of conversion for both is very close (0.8 for first and 0.7 for second party) like in 2012 and 1998. Second, when the difference between the vote share increases slightly more, the conversion ratio between the leading and opponent parties widens hugely, like in 1993 (1.1 for leading and 0.2 for lagging party). The difference between the vote share of these two parties in the case of first pattern was 4% only and was more than 5% in the case of the second pattern (an astounding 13% in 1993).

Due to the situation at the ground, it is highly likely that the second pattern will occur. The average of conversion for the years falling under second pattern is calculated. The leading and lagging parties’ conversion ratio are clubbed together irrespective of the parties itself (BJP or Congress). As in this Himachal election, BJP is expected to be the leading party, the average of the leading party conversion ratio would be attributed to it, which is 1 and similarly for Congress (the lagging party conversion ratio, which is 0.4). Although Left parties and BSP contested all the elections over these years but they were never a significant force in the fray except 2007 in which BSP got 7% vote share (1 seat).

There was a 4.3 percentage point (pp) increase in favor of BJP in the 2014 general election as compared to 2009. This increase I attribute to BJP this election as the Modi wave component. There are other factors as well which go in favor of BJP and those are anti-incumbency of 5 years and corruption charges against the incumbent Chief Minister Virbhadra Singh, aged 83. These all together, add to advantage BJP and a same 4.3 pp increase has been attributed to these factors.  There was a loss of 4.5 pp vote share of Congress in 2014 general election as compared to 2009 Himachal election. The total increase in vote share of BJP in the 2017 Himachal assembly election as compared to 2012 is 8.6 pp and total decrease in vote share of Congress is only 4.5 pp, thanks to the extremely feeble third front.

The predicted vote share for BJP and Congress in Himachal is 47% and 38.3% respectively which translates into 49 and 14 Seats Respectively


The period of analysis has been 1990 to 2012. Except 1990, in all 5 assembly elections the vote share of BJP was 10 pp above that of Congress. The trend has been very consistent in favor of BJP. As described above, the conversion ratio of leading and lagging parties is clubbed together. In case of Gujarat, for all the 6 elections, BJP was the leading party with an overall edge of around 1-point conversion ratio in every election with respect to Congress. Effectively, it is averaging the conversion ratio of BJP and Congress over the years. The vote share to seat conversion ratio of BJP and Congress for the target year (2017) is 2.5 and 1.5 respectively. The task at hand is to predict the vote share for the parties in the 2017 election and then using the above-mentioned ratio, respective seats can be found.

There are two important factors which would have an impact on the election outcome. Modi wave (Gujarati pride: an ordinary son of Gujarat is the Prime Minister of India) and Patidar’s anger against the state government. There was an increase of 13.6 pp in vote share for BJP and a decrease of 9.9 pp in vote share for Congress in 2014 general election with respect to 2009. The increase in vote share to BJP is classified as Modi wave, as explained above. The only difference in the case of Gujarat is that the face of Modi is not new in Gujarat. He was the face of BJP in the 2012 election, so the increase in vote share from 2012 election would not be equivalent to 13.6 pp. The effect is deflated by 50%. Effectively, Modi wave would add 6.8 pp to the BJP vote share of 2012 assembly election.

According to a Business Line report1, Patidars constitute 15% of the total population of the state. Majority of this class has been the trusted voters of BJP for over two decades. The community started protesting for reservation in 2015 and government actions thereafter angered them. It has been a long time that BJP is trying to pacify them, but a section among them is still very disappointed with the ruling party. It is expected that this section headed by Hardik Patel would vote against BJP in favour of Congress. I assume this segment as 25% of their total population. Electors are 63% of the total population in Gujarat. The same proportion of electors is assumed for Patidars as well. The calculation shows that this section constitutes 2.4% vote share.

I assume that this block has traditionally voted for BJP in the past, but now would switch to Congress. The net effective increase in vote share for BJP is 4.4 pp and similarly the decrease of vote share for Congress is 7.6 pp. The two other caste leaders Alpesh Thakor and Jignesh Mevani are also supporting Congress, but they don’t have any concrete agenda, so it is assumed that they would not be able to alter the situation on ground significantly.

The predicted vote share for BJP and Congress in Gujarat is 52.3% and 31.4% respectively which translates into 130 and 47 Seats Respectively


Table 1: Predicted Vote Share and number of Seats for BJP and Congress in 2017 assembly election




Vote Share (%)

Number of Seats

Vote Share (%)

Number of Seats

Himachal Pradesh










Sources: Election Commission of India, Census 2011




It demonstrates that BJP is going to have a very happy new year this time. Overall, this year has been very encouraging for them starting from Uttar Pradesh and Uttarakhand elections. The 2019 general election is only one and half year ahead, so a positive result in these upcoming elections would act as a catalyst in their preparations, whereas, overcoming these defeats before the Lok Sabha election would not be easy for Congress.


Previous «
Next »
Sriramjee Singh

IIT Kharagpur. Iowa State University, USA Political Analyst, Economist, Data Scientist and a passionate Programmer
  • facebook

Leave a Reply

Your email address will not be published. Required fields are marked *