Green Million — Wieliczka's Proportional-Algorithm Participatory Budget (Method of Equal Shares)

In April 2023, the Polish town of Wieliczka ran an experimental edition of its participatory budget — 'Zielony Milion' ('Green Million') — allocating PLN 1,000,000 (about EUR 220,000) among proposals submitted by residents. Instead of the town's usual plurality voting rule, the election used the Method of Equal Shares (MES), a proportional budget-allocation algorithm developed by researchers including Prof. Piotr Skowron at the University of Warsaw's Faculty of Mathematics, Informatics and Mechanics under the ERC-funded PRO-DEMOCRATIC project.
6,586 residents voted across 64 submitted projects; MES selected 30 winning projects worth PLN 995,079, compared with just two large projects that would have won under the previous standard rule. Published results show the share of voters who received none of their preferred projects fell from 28% (under the old method) to 18% under MES, average voter satisfaction rose by about 10%, and the maximum distance from a resident to their nearest funded project shrank from 6.1 km to 3.4 km, indicating better geographic fairness across the municipality.
The same algorithm has since been used in real participatory budgets in Świecie (Poland), Aarau and Winterthur (Switzerland), and Assen (Netherlands), suggesting genuine transferability. Wieliczka ran Green Million as a one-off experimental pilot alongside its regular participatory-budget cycle rather than replacing it, so it is not yet confirmed as the town's permanent method.

Read the full analysis: https://equalshares.net/elections/zielony-milion/