Stadtidee Aarau — Switzerland's First City-Wide Participatory Budget Using the Method of Equal Shares

Between 2023 and 2024, the Swiss city of Aarau ran Stadtidee, its first city-wide participatory budget, inviting residents to submit neighbourhood improvement ideas and vote on a CHF 50,000 budget. Of 161 proposals submitted, 33 were shortlisted for a public vote in which each of Aarau's roughly 22,000 residents could distribute 10 points across their preferred ideas.
Rather than a simple plurality count, the city used the Method of Equal Shares (MES) — the same proportional algorithm piloted in Wieliczka, Poland — to decide the winners. Around 1,700–1,800 residents voted. MES funded 17 projects spread across all city districts, compared with an estimated 7 (larger, costlier) projects that plurality voting would have selected. By the end of 2024, 9 of the 17 funded projects had been realised, 5 were being extended into 2025, and 3 could not be completed.
The trial was documented in a peer-reviewed paper at the AAAI/AIES conference (Yang, Hausladen, Peters, Pournaras, Hänggli Fricker and Helbing) and in the city's own closing report. Aarau's authorities committed to repeating Stadtidee every four years, with the next edition due in 2027 — an institutional commitment to recurrence, though only one full cycle has been completed to date.

Read the full analysis: https://www.aarau.ch/politik-verwaltung/smart-city/stadtidee.html/1994