In short: In a typical federal vote in the 2020s, the city of Zurich deviates 13 percentage points from the national result — twice as much as in the 1970s.


Does the city of Zurich vote differently from Switzerland? If so: by how much, and is it changing?

Context
In Swiss federal votes, all eligible voters across the country decide on the same ballot — whether popular initiatives, referendums, or constitutional amendments. Results are tallied nationally and by municipality. This allows a direct comparison: How did the city of Zurich vote, and how did Switzerland as a whole?

For every federal vote since 1933, the difference between the city of Zurich’s result and Switzerland’s can be calculated — regardless of whether Zurich voted more or less in favour. What matters is the size of the deviation.1

Median Deviation: City of Zurich vs. Switzerland
Federal votes, median absolute difference in percentage points per decade.
1970s
5.6 PP (86 votes)
1980s
7.7 (62)
1990s
7.9 (100)
2000s
8.3 (93)
2010s
9.0 (83)
2020s
12.8 (59)
Absolute difference |ZH − CH| in percentage points, median per decade. Source: Open Data City of Zurich.

In the 2020s, the city of Zurich deviates 12.8 percentage points from the Swiss result in a typical vote. In the 1970s, it was 5.6. Each decade is higher than the last.2

In the 2020s, the deviation rises from 9.0 to 12.8 percentage points. So far, 59 votes are available for this decade. Whether the increase holds with more data remains open.

The five largest deviations since 2020:

BallotCity of ZurichSwitzerlandDifference
Climate Policy Initiative (Nov. 2025)41.5 %21.7 %+19.8 PP
Climate Fund Initiative (Mar. 2026)49.1 %29.3 %+19.8 PP
Individual Taxation (Mar. 2026)72.9 %54.3 %+18.6 PP
Property Tax on Second Homes (Sep. 2025)42.1 %57.7 %−15.6 PP
E-ID Act (Sep. 2025)63.9 %50.4 %+13.5 PP

The numbers show the size of the deviation. What causes it — demographics, urbanisation, the mix of ballot topics — cannot be determined from this measurement alone.

Open Questions
Only six years of data are available for the 2020s so far. The measurement shows the size of the deviation, not its cause.

  1. The measure used is the absolute difference between the yes-vote share of the city of Zurich and that of Switzerland, regardless of direction: |yes% ZH − yes% CH|. Summarised as the median per decade. The median captures the typical deviation and is robust against individual outliers. ↩︎

  2. Open Data City of Zurich — Vote Results since 1933. Own analysis: 587 federal votes since 1933, of which 483 since 1970. All values calculated from city-wide results. ↩︎