Why pollsters erred in most result predictions

In the weeks leading up to the just-concluded elections, polls across the country predicted an easy sweep for Azimio One Kenya alliance leader Raila Odinga.

However, pollsters apparently missed the preferences of a large portion of the last week’s elections indicating a larger, more systematic issue, one that is unlikely to be fixed anytime soon.

The pollsters largely got it wrong when they showed Raila in the lead only for the outgoing Deputy President William Ruto to emerge the winner after he got 50.49 per cent of the votes.

On Monday, Independent Electoral and Boundaries Commission (IEBC) Chairman Wafula Chebukati declared Ruto president-elect after garnering 7.1million votes against Raila Odinga’s 6.9million.

However, just five days to the elections, pollsters placed Raila ahead of Ruto stating that he had a high chance of winning.

Before election day, the Ipsos poll, Trends and Insights for Africa (Tifa) placed Raila at 46.7 per cent ahead of Ruto who had 44.4 per cent, a slim 2.3 per cent margin.

The poll showed Prof George Wajackoyah of Roots party had 1.8 per cent while Waihiga Mwaure trailed at 0.1 per cent.

According to the poll done between July 31 and August 1 and had 2,268 respondents, Raila was to achieve a win of 53 per cent if undecided voters were not factored in the tabulation of support for either candidate. It placed Ruto second with 45 per cent support.

With the undecided voters involved, Raila was still ahead with 49 per cent, and Ruto second at 41 per cent support.

In 2017, Infotrak had conducted a survey predicting a tight presidential contest, with Raila in the lead (49 per cent) against President Uhuru Kenyatta (48 per cent).

However, Ipsos survey showed that Kenyatta had a 47 per cent rating among registered voters ahead of Raila who scored 44 per cent in a study conducted between July 22 and 30.

Both Ipsos and Infotrak surveys had indicated that neither Raila nor Kenyatta would attain the 50 per cent plus one vote rule and had foreseen a possible run-off, this never materialised.

When elections were held on August 8, 2017, the results were different. Kenyatta was declared the winner of the presidential contest with 54.1 per cent, against Raila’s 44.9 per cent.