Introducing the HI-RES SIKAP of Indonesian voters

“Data! Data! Data! ― I can’t make bricks without clay,” Sherlock Holmes was described saying in Sir Arthur Conan Doyle’s The Adventure of the Copper Beeches. For students of Indonesian politics, public opinion data is the clay we need to make sense of this year’s national and local elections. The stakes are high: over the past few years, Indonesia has experienced what many observers regard as a democratic erosion. Consider the recent Constitutional Court ruling that paved the way for Gibran Rakabuming’s inclusion on the ballot as a vice presidential candidate. Was this episode a simple case of elite politics and manoeuvring on the part of Jokowi? Or does it reflect a declining public appetite for the burdens associated with the rule of law? To answer these sorts of pressing questions, we need access to publicly available survey data.

To be sure, there exist several such sources, including the World Values Surveys (WVS), the Asia Barometer survey, the USAID Demographic and Health Surveys, the Indonesian Family Life Survey (IFLS), and the Pew Center’s study of the World’s Muslims, to list some notable examples. But these surveys tend to be one-off snapshots—a fact that undermines their utility for observing how Indonesians’ attitudes are unfolding in real time and in response to external events. (The World Values Survey was most recently conducted in Indonesia in 2018, for example.)

With an eye towards encouraging data-driven research, since November 2023 we have been conducting weekly public opinion surveys, gauging the attitudes of 1,650 Indonesian adults each week. We will continue to conduct weekly surveys until January 2025, aiming to survey approximately 95,000 Indonesian adults over the course of 58 weeks. Importantly, we will make the data freely available to interested researchers. We call this initiative High-Frequency Surveys on Indonesians’ Knowledge of and Attitudes on Politics (HI-RES SIKAP).

Below, we describe the survey design, the sample, two use case examples, and how to access the data.

The design

The SIKAP project draws inspirations from the Nationscape study run by the Democracy Fund and UCLA. As co-Principal Investigators, we contribute equally to the project and would like to acknowledge funding from the Singapore’s Ministry of Education and the National University of Singapore that has made the project possible. The key component of SIKAP is the weekly online surveys that we have been running and will continue to run for a total of 58 weeks, from 27 November 2023 to 5 January 2025. This period, as students of Indonesia will immediately notice, covers several politically significant events, such as the presidential election in February 2024, the inauguration of Prabowo Subianto as president in October 2024, and the simultaneous local elections in November 2024. We developed a set of core modules that are asked across all 58 surveys. That the surveys have overlapping core questions, and are fielded weekly means that SIKAP offers insights on how voters’ attitudes on an issue may change as a response to a political event.

Sampling methods

Each SIKAP wave collects data from a fresh sample of 1,650 respondents, provided by the online panel vendor Cint (formerly known as Lucid). In the ideal case, by the conclusion of the project we will have collected data from 95,700 unique respondents. However, for several practical reasons, we allow respondents to be interviewed again after eight weeks have passed since their last interviews. This gives us the best features of cross-sectional and longitudinal data. Aiming for a fresh sample in each wave enables us to capture a diverse pool of respondents. Allowing for multiple interviews, meanwhile, enables us to track how social and political attitudes of re-interviewed respondents might change over the course of 58 weeks. Online surveys are not representative of the Indonesian population. Many voters do not have internet access and the underlying factors that drive such access may be correlated with the attitudes in which we are interested in measuring. For example, our sample is more educated than the population. Nevertheless, we prioritised implementing quotas that enabled us to achieve representational parity on other crucial variables: gender, age, and region. These quotas improve the representativeness of our sample and, at the same time, still ensure that each survey wave can finish in one week.

The lack of representativeness of our sample has significant implications. Researchers who wish to use our data are solely responsible for the content of their analyses, but in general we would discourage using the SIKAP data to present simple descriptive statistics or to extrapolate those statistics to the population. For example, it is not advisable for researchers to analyse our presidential vote preference question and then extrapolate that to argue for how many voters support Anies Baswedan, Prabowo Subianto, or Ganjar Pranowo. That kind of exercises requires a different type of sampling method. Instead, we believe our data is particularly useful for two types of exercises.

Use case: affective polarisation

How do supporters of a presidential candidate feel toward supporters of other presidential candidates, and how do these feelings change over the course of the election? This is one of the questions that we can examine using the SIKAP data. SIKAP includes questions about respondents’ presidential vote preferences. It also includes questions that tap into the respondents’ feelings toward supporters of the three presidential candidates that competed in the February 2024 presidential elections. Respondents may indicate their feelings toward supporters of each of the candidates on a 5-point scale that ranges from a strong dislike to a strong like. Figure 1 presents levels of affective polarisation among the three candidates’ supporters from the first week of SIKAP (27 November 2023–3 January 2024) to the tenth week (29 January 2024–4 February 2024).