motief/reports/overton_window/README.md

Overton Window Analysis — Reading Guide

This directory contains the complete Overton window analysis: a quantitative investigation into whether the Dutch parliamentary center shifted rightward between 2016 and 2026.

Verdict: The Overton window did not shift right. Right-wing parties moderated toward it. The shift may be temporary.

Where to Start

1. Interactive Article — The narrative spine. 9 sections with interactive Plotly charts telling the story from question to answer. Render with quarto render overton_window.qmd.

2. Synthesis Report — The detailed synthesis of all indicators, uncertainty hierarchy, and the "acceptance through moderation" verdict.

3. HTML Dashboard — Standalone visual report with gravity-controlled charts, 2D extremity heatmap, and three example motions.

Live Exploration

Explore the data interactively in the Stemwijzer Explorer (uv run streamlit run Home.py):

• Overton tab — Centrist support trends, right-wing motion browser, summary statistics
• Kompas tab — SVD party positions (the axes behind the spatial divergence finding)
• Trajectories tab — Party drift over time (with 2024 breakpoint annotation)
• SVD Components tab — Which motions drive each ideological axis

Appendix Reports

Each report covers one analytical dimension:

Report	What it answers
Breakpoint Analysis	When did centrist support surge? How much?
Temporal Trajectory	Quarterly resolution — was it gradual or sudden?
Causal Timing	Electoral jump vs coalition-driven?
SVD Drift	Did party positions converge or diverge?
2D Extremity Temporal	Did motion content become more extreme?
2D Correlation	Are style and substance independent? (r=0.43)
Party Differentiation	Which right-wing party drove the shift? (JA21)
Left-Wing Response	Did left parties harden opposition?
Mechanism Classification	How do right-wing motions gain centrist support?
Mechanism Validation	Inter-rater reliability (κ=0.41)
Voting Margin	Continuous margin vs binary pass/fail
Success Correlation	Do high-CS motions actually pass more?
Predictive Model	Can we predict centrist support? (AUC=0.81)

Methodology

• 7-step methodology: docs/solutions/best-practices/overton-window-shift-methodology-2026-05-24.md
• Extended analysis: docs/solutions/best-practices/overton-extended-analysis-methodology-2026-05-26.md
• Domain decomposition: docs/solutions/best-practices/domain-decomposition-hidden-overton-variance-2026-05-25.md

Reproducibility

Regenerate all reports with:

uv run python analysis/right_wing/build_all_reports.py --skip-llm

Status

See STATUS.md for the complete analysis status, data sources, and canonical numbers.