Exit Polls: Assessing Reliability, Addressing Limitations, and Exploring Improvements
It is better to be approximately correct than to be precisely wrong.
The Reliability of Exit Polls: An Analysis Post-Lok Sabha Voting
Introduction
Exit polls are a significant part of the Indian electoral landscape, providing pre-counting indications of voter sentiment and potential election outcomes. Following the final phase of polling in the protracted 7-phase Lok Sabha elections on 1st June, various news channels have released their predictions and projections. Most of them have projected a comfortable victory for the NDA, led by PM Modi’s BJP, prompting some prominent opposition leaders to question their intent as well as their validity. Despite their prominence and popularity, a critical examination reveals significant gaps in the methodology and transparency of these exit polls, highlighting areas where there is much scope for improvement.
Lack of Transparency in Methodology
Major Exit Polls and Their Approaches
Several major exit polls have employed various methodologies to gather and analyse voter data. For instance:
News18 Mega Exit Poll: Conducted across 21 states and 518 seats, with over 95,000 voters surveyed. This poll utilised random sampling in Vidhan Sabha constituencies, door-to-door interviews, and interviews at polling stations. They ensured quality control through geo-tagging and telephonic back-checks.
India Today-Axis My India Exit Poll: This poll involved interviews with voters exiting polling booths across multiple states, using random sampling techniques and applying statistical models for seat and vote share estimates.
ABP News-C Voter Exit Poll: Known for face-to-face interviews at polling stations, employing random and stratified sampling methods, and using proprietary statistical models.
Republic TV-P Marq Exit Poll: Conducted interviews with voters exiting polling booths, using random and stratified sampling techniques, and applying vote-swing calculations.
Missing Details: Confidence Levels and Margins of Error
While these methodologies sound robust, a crucial gap remains: most exit polls do not explicitly mention the confidence levels, margins of error, or even the size of their samples, which, in any case, would be microscopic compared to the electorate size of around 100 crore. This lack of transparency, or proactive disclosure, raises questions about the reliability of their projections. Knowing the sample size and understanding the confidence level and margin of error is essential to gauge the accuracy and precision of any statistical prediction, especially in elections.
Aggregated Figures vs Individual Constituencies
Exit polls usually provide aggregated figures for states or the entire nation, which can be misleading. While they might achieve high accuracy in macro results, they often fail at the micro-level, particularly in individual constituencies. This discrepancy underscores the necessity for detailed projections at the constituency level to provide a clearer picture.
In other words, the true test of these exit polls would be their constituency-wise projection of the winners. Otherwise, a correct prediction might be akin to reaching the right answer in a school maths class but getting the entire working wrong. Therefore, it would be in their own interest to stick their necks out and present their predicted winners for all the 542 (543-1) Lok Sabha constituencies. Anything less than that, in our humble opinion, is just crystal gazing and number crunching or juggling.
Historical Accuracy and Future Projections
Historically, exit polls have had a mixed track record. They have gone horribly wrong on several occasions, causing considerable confusion and speculation. Their predictive accuracy is often only validated until the forenoon of the 4th of June when actual trends start emerging. By the afternoon, as the real results come in, these polls often find themselves at odds with the official outcomes, prompting analysts to retrospectively justify their projections.
Summing Up
Exit polls serve as an intriguing yet imperfect tool in the electoral process. The current practice of not disclosing complete methodological details, particularly the confidence levels and margins of error, diminishes their credibility. Until exit polls provide detailed projections at the constituency level and disclose all relevant statistical parameters, their reliability will remain questionable. As the actual election results unfold, the shortcomings of these exit polls become evident, highlighting the need for greater transparency and methodological rigour in future polling exercises.
In any case, their lifespan is limited, and one should not grudge them a few days of fame.
