In the latest Sri Lanka Opinion Tracker Survey (SLOTS) polling in May 2023, support amongst likely voters for NPP/JVP fell from 30% in April to 23% in May. Support for SJB also dropped by 4 points to 26%. The UNP and SLPP shares increased by 4 points to 13% and 10% respectively.
The trends show support for UNP and SLPP increased during March 2023–May 2023 whilst support for the NPP/JVP declined over the same period after peaking at 41% in February 2023. Support for SJB fell a little in May 2023, but since October 2022 its support has been relatively stable, fluctuating in the range of 25–30%.
IHP is an independent, non-partisan research centre based in Colombo, Sri Lanka. The SLOTS lead investigator is Dr Ravi Rannan-Eliya of IHP, who has trained in public opinion polling at Harvard University and has conducted numerous surveys over three decades.
SLOTS combines interviews from a national sample of adults (ages 18 and over) reached by random digit dialling of mobile numbers, and others coming from a national panel of respondents who were previously recruited through random selection. IHP estimates voting intent using an adaptation of Multilevel Regression and Post-Stratification (MRP), with multiple imputation to account for uncertainties in its modelling, exploiting data from all SLOTS interviews to estimate voting in a particular month.
The May 2023 MRP estimates are based on 630 interviews conducted in May 2023, and 11,897 interviews conducted overall from 31 August 2021–19 June 2023, with a margin of error assessed as 3–5% for the NPP/JVP, SJB, UNP and SLFP, and 1–3% for the other parties. As the May update uses a more recent data set than the previous update, there are small changes in estimates of voting shares for previous months. Additionally, the number of stochastic simulations used in the modelling was increased from 30 to 100, yielding a small improvement in the precision of estimates of voting shares and of margins of error.
MRP is a method that is increasingly used by polling firms in other countries to leverage small samples, most notably by YouGov which used it to forecast results of the UK Brexit Referendum and recent UK general elections. All estimates are adjusted to ensure the sample matches the national population with respect to age, sex, ethnicity, socioeconomic status, education, geographical location, and voting in the 2019 Presidential and 2020 General Elections.
The SLOTS has been funded by the Neelan Tiruchelvam Trust, the UK National Institute for Health and Care Research (NIHR), The Asia Foundation in Sri Lanka, and others, but the sponsors play no role in the study design, analysis, or interpretation of findings. Interested parties can contact IHP for more detailed data and results.
Date: 30 June 2023
Time: 12:01 AM Sri Lanka Time
FOR FURTHER INFORMATION CONTACT
Email: dalreen ‘at’ ihp.lk
TO CONTACT LEAD INVESTIGATOR
Dr. Ravi Rannan-Eliya
Email: ravi ‘at’ ihp.lk Twitter: @ravirannaneliya