The OECD Trust Survey, carried out by the OECD Directorate for Public Governance, had around 2 000 respondents per country in the twenty-two participating OECD countries: Australia, Austria, Belgium, Canada, Colombia, Denmark, Estonia, Finland, France, Ireland, Iceland, Japan, Korea, Latvia, Luxembourg, Mexico, the Netherlands, New Zealand, Norway, Portugal, Sweden and the United Kingdom. In Brazil, the survey was implemented online with a final sample of 4 140 respondents.
The survey process and implementation were guided by an Advisory Group comprised of public officials from the Controladoria-Geral da União (CGU), representatives of National Statistical Offices from Brazil and Colombia, and international experts, including representatives from Latinobarometer, the Americas Barometer (LAPOP) and the Inter-American Development Bank.
The survey was conducted online by the survey company Netquest between 7 April and 6 May 2022, sourced by Netquest’s and its partners panel in Brazil.
The Trust Survey questionnaire was prepared in English, translated into Portuguese and reviewed by CGU’s public officials and public governance specialists that were also part of the Advisory Group established for the Trust Survey in Brazil.
The OECD Trust Survey uses an eleven-point scale for the response choices on questions about levels of trust and drivers of trust, following reviewed best practices (OECD, 2017[1]) and applications in country studies in Korea, Finland, Norway, and New Zealand (OECD/KDI, 2018[2]; OECD, 2021[3]; OECD, 2022[4]; OECD, 2023[5]). A numerical 0-10 scale with verbal scale anchors is recommended and used here for survey questions on trust and drivers of trust, as it allows for variance in responses, increases overall data quality and complexity, and facilitates translatability across languages. This presents a more nuanced analysis, allowing respondents to provide a “neutral” response that other surveys do not allow.
The online survey uses a non-probability sampling approach, based on ex-ante country-level quotas representative of the Brazilian population by age, gender, level of education, socioeconomic category and region. The quotas were derived from national estimates of these population groups based on probabilistic surveys and census data. The non-probability sample construction was the most feasible option for the OECD Trust Survey given its simplicity, timeliness, and lower cost. The implementation in Brazil largely follows the same quota design as in other participating countries, with one exception. Instead of using income as a soft quota (bottom 20%, middle 60% and top 20%) (Nguyen et al., 2022[6]), in Brazil socioeconomic categories were used following the Brazil Economic Classification Criteria (Critério Brasil-ABEP). The Brazil Economic Classification Criteria classifies households into five groups (A-E) based on their estimated purchasing power. It assesses access to public utility services, level of education and possession of several amenities (such as bathroom, dishwasher, freezer, etc.) (ABEP, 2021). The quotas were derived from national estimates of group prevalence based on probabilistic surveys and census data.
Responses were collected until the country-specific quotas were filled and post-stratification weights were calculated using the “random iterative method (RIM)” based on age, gender, education, region and socioeconomic status. The median interview duration was 19 minutes.