Secondary Outcomes (explanation)
Prior Beliefs (RQ1 and RQ2)
Prior beliefs are elicited before treatment exposure using a dynamic slider-and-pie-chart interface. Respondents are shown a fully grey pie chart and a slider set to zero; as they move the slider, the chart updates in real time to reflect their input. No anchor value is provided prior to elicitation, to avoid anchoring bias. Respondents subsequently report their confidence in the estimate by indicating by how many percentage points they believe they may be mistaken. These prior belief measures serve two purposes: as secondary outcomes to identify the correlates and determinants of misperception, and as moderators in heterogeneous treatment effect analyses, where prior belief distance from the true value is the primary pre-specified moderator.
For RQ1, a misperception score is constructed as the difference between the respondent's prior belief and the ISTAT (2025) true value. A composite measure of prior beliefs about peer engagement and voting will also be constructed. For RQ2, prior beliefs are arm-specific: the estimated share of false accusations (Arm 1), the estimated share of violence cases reported to police (Arm 2), the estimated share of young males and females agreeing that feminism has gone too far (Arm 3), and the estimated share of young males identifying as gay or bisexual and young females as lesbian or bisexual (Arm 4).
Behavioural Demand Outcomes (RQ1)
Willingness to sign the youth-quota petition, demand for additional information, and demand for the signing link are elicited sequentially at the end of the survey. These outcomes capture low-cost behavioural intentions and revealed interest beyond self-reported engagement likelihood. Respondents who request additional information will receive an email from the survey company containing the relevant links; researchers will not personally contact respondents. These outcomes are analysed as binary variables.
Peer Norm Beliefs and Turnout Expectations (RQ1)
The posterior belief about the share of young people discussing politics weekly is elicited as a quantitative point estimate after treatment exposure and serves as both a manipulation check and a secondary outcome capturing descriptive norm updating. The expected share of peers voting at the referendum captures downstream social norm updating beyond the respondent's own engagement intentions, and will be compared to official turnout statistics where available.
Wave 2 Outcomes (RQ1)
Self-reported referendum voting behaviour is collected in Wave 2, administered shortly after the March 2026 constitutional referendum. This outcome is subject to social desirability bias, which will be acknowledged in interpretation. Because Italian law requires citizens to vote in their municipality of registration, respondents who have relocated — a substantial share among young adults — cannot vote without travelling back, which is expected to attenuate treatment effects on actual turnout for this subgroup. Wave 2 analyses for RQ1 are designated exploratory given that the recontacted subsample of approximately 1,000 respondents is underpowered to detect effects on actual voting reliably.
Demand for Reports (RQ2)
Respondents are offered the opportunity to receive the reports cited in the discrimination treatment arms. Demand is measured as a binary indicator of whether the respondent requests the relevant report. These outcomes capture revealed interest in gender-related information and serve as low-cost behavioural complements to the attitudinal primary outcomes.
Mechanism Indices (RQ1)
Three mechanism indices are constructed to capture the psychological and attitudinal pathways through which the information treatments may affect political engagement. All indices are computed as the simple mean of standardised components and re-standardised relative to the control group. All variables are recoded so that higher values correspond to greater political engagement, efficacy, or institutional trust.
The Trust and Institutional Responsiveness Index captures whether treatment shifts perceived legitimacy of political institutions and perceived government responsiveness to youth concerns. The Political Motivation Index captures changes in political interest, free-riding attitudes, and the social norms around voting, including shame associated with voting when peers abstain and the prioritisation of social activities over civic participation. The Political Efficacy Index captures both internal efficacy (the respondent's sense of personal competence to engage in politics) and external efficacy (the respondent's belief that participation can influence government decisions).
These indices are examined as secondary outcomes to distinguish between competing mechanisms — in particular, the descriptive norm channel (whereby observing high peer participation strengthens legitimacy and efficacy) and the backlash or civic duty channel (whereby observing low peer participation increases perceived pivotality and personal motivation). Predicted directions by treatment arm are reported in the pre-analysis plan and summarised in Table 3 of the associated paper.
Measurement and Scaling
All secondary and mechanism outcomes measured on Likert scales are analysed as continuous variables in the main specification, with binary and standardised versions reported alongside. Mechanism indices are standardised using the control group mean and standard deviation. Demand outcomes are binary. Wave 2 outcomes are analysed using the same OLS specification as Wave 1, with treatment assignment from Wave 1 as the key independent variable.