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PRESS RELEASEEMBARGOED UNTILFOR FURTHER INFORMATION CONTACT

Date: 26 January 2024
Time: 12:01 PM Sri Lanka Time

Dalreen Barthelot
Email: dalreen ‘at’ ihp.lk

TO CONTACT LEAD INVESTIGATOR
Dr. Ravi Rannan-Eliya
Email: ravi ‘at’ ihp.lk Twitter: @ravirannaneliya

NPP/JVP on 39% of all adults, ahead of SJB(27%) and SLPP (10%) in December ’23
IHP MRP General Election Voting Intentions Update December
2023
The latest estimates from IHP’s revised SLOTS MRP model (revised 01/2024) show that theNPP/JVP maintains a lead in General Election voting intent with 39% of Sri Lankan adults inDecember 2023. This was significantly ahead of the SJB on 27%, the SLPP on 10%, the UNP
on 6%, and ITAK and SLMC on 3% each. The December estimates are provisional and areassociated with a margin of error of 2.0–3.5% for the four leading parties.

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The revised IHP SLOTS model estimates reveal more clearly that the current NPP/JVP leadis based on a continuous rise in support since early 2022. The SJB has also increased itssupport, but a slower pace, lying in second place since mid-2022. The December 2023
estimates also confirm a decline in support for the UNP since July 2023, with SLPP support
holding steady.

These results are based on a major revision of the IHP SLOTS MRP model, intended tosmooth monthly changes and reduce monthly fluctuations due to sampling noise. Unlike
previous months which highlighted voting intent in likely voters, these estimates are for alladults. IHP is working on improving its likely voter model and will resume release of voting
intent in likely voters in a future update. But it should be noted that differences in voting intent
shares between all adults and likely voters have typically been 1–2% for most estimates in thepast two years.
This December 2023 update is based on 14,941 interviews conducted with adults across Sri
Lanka since Oct. 2021, with 522 interviews carried out in Dec. 2023. IHP’s SLOTS MRPmethodology first estimates the relationship between a wide variety of characteristics about
respondents and their opinions – in this case, ‘If there was a General Election today, whichparty would you vote for– in a ‘multilevel statistical model’. It then uses a large data file that iscalibrated to the national population to predict voting intent in each month since Oct. 2021,
according to what the multilevel model says about their probability of voting for various parties(‘post-stratification’) at each point in time. The multilevel model was estimated 100 times toreflect underlying uncertainties in the model and to obtain margins of error.
Previous reports available from ihp.lk
Institute for Health Policy, March 2023, “IHP MRP Voting Intentions Estimates February
2023. Voters consolidate around the NPP/JVP, SJB and ITAK, with NPP/JVP taking a clearlead”, SLOTS Report #2023-06.
Available at: https://ihp.lk/publications/docs/SLOTSReport202306.pdf
Institute for Health Policy, April 2023, “Little change in voting preferences in March, withNPP/JVP maintaining a clear lead over SJB, amidst possible signs of a UNP rise. IHP MRPGeneral Election voting intentions update March 2023”.
Available at: https://ihp.lk/news/pres_doc/IHPPressRelease20230419.pdf

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Institute for Health Policy, May 2023, “NPP/JVP maintains a lead, but loses support to UNP
and other parties, whilst SJB flatlines. IHP MRP General Election voting intentions updateApril 2023”.
Available at: https://ihp.lk/news/pres_doc/IHPPressRelease20230525.pdf
Institute for Health Policy, June 2023, “NPP/JVP support fell to 23% behind SJB on 26%,
whilst support for UNP and SLPP rises amongst likely voters during May 2023. IHP MRPGeneral Election voting intentions update May 2023”.
Available at: https://ihp.lk/news/pres_doc/IHPPressRelease202306301.pdf
Institute for Health Policy, July 2023, “Support for NPP/JVP and SJB fell, with evidence ofgrowing vote disillusionment with all established parties in June 2023. IHP MRP General
Election voting intentions update June 2023”.
Available at: https://ihp.lk/news/pres_doc/IHPPressRelease20230727.pdf
Institute for Health Policy, August 2023, “Support for major parties changes little in July, withNPP/JVP and SJB ahead, but large numbers of voters uncommitted. IHP MRP General
Election voting intentions update July 2023”.
Available at: https://ihp.lk/news/pres_doc/IHPPressRelease20230821.pdf
Institute for Health Policy, September 2023, “NPP/JVP retain an edge over the SJB amongstvoters in August. IHP MRP General Election voting intentions update August 2023”.
Available at: https://ihp.lk/news/pres_doc/IHPPressRelease20230925.pdf
Institute for Health Policy, October 2023, “NPP/JVP leads with 42% of likely voters, ahead ofthe SJB (22%) and UNP (13%) in September. IHP MRP General Election voting intentions
update September 2023”.
Available at: https://ihp.lk/news/pres_doc/IHPPressRelease20231023.pdf
Institute for Health Policy, November 2023, “Little change in voter intentions in October, withNPP/JVP consolidating its lead at 40%. IHP MRP General Election voting intentions update
October 2023”.
Available at: https://ihp.lk/news/pres_doc/IHPPressRelease20231123.pdf

About IHP
IHP is an independent, non-partisan research centre based in Colombo, Sri Lanka. TheSLOTS 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.

Methodology details
SLOTS combines interviews from a national sample of adults (ages 18 and over) reached byrandom digit dialling of mobile numbers, and others coming from a national panel ofrespondents who were previously recruited through random selection and face-to-faceinterviews. IHP estimates voting intent using an adaptation of Multilevel Regression and PostStratification (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 December 2023 MRP estimates are based on 522 interviews conducted in December
2023, and 14,941 interviews conducted overall from 1 October 2021–7 January 2024, with aPage 3 of 4

margin of error assessed as 0.8–3.4% for the NPP/JVP, SJB, UNP, SLPP, SLFP, ITAK,SLMC, CWC, and 4% for the “other” parties. The December update uses a revised model, soestimates will be smoother and will differ a little from previous estimates. A total of 100
stochastic simulations were used in the modelling to estimate 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.

FundingThe SLOTS survey has previously 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. Current fieldwork is financed by the IHP Public Interest Research Fund and others.
The sponsors play no role in the study design, analysis, or interpretation of findings.
Furthermore, the survey findings do not necessarily reflect the views or positions of past andpresent funders. Interested parties can contact IHP for more detailed data and results.

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