Update Log

2026-07-15

New: State Wahlkreis elections in the R package (gerda 0.7.1)

• State Landtag elections at the Wahlkreis level – ltw_wkr_unharm (vote shares) and ltw_wkr_unharm_long (vote counts), 1990–2026, all 16 states, with first and second votes. The state counterpart to the federal Wahlkreis data.
• Removed the county_elec_harm_21 entry from the R package, which pointed to a file that was never published; use county_elec_harm_21_cty or county_elec_harm_21_muni instead.

2026-07-02

Sachsen-Anhalt mayoral elections — 2019 – 2026 coverage from the official StaLA dataset. ST (state 15) mayoral coverage jumps from 66 Gemeinden × 2024 – 2026 (the earlier portal scrape) to 218 Gemeinden × 2019 – 2026 — the full universe of currently-serving hauptamtliche and ehrenamtliche mayors.

• Primary source: the Statistisches Landesamt Sachsen-Anhalt Dezernat 13 “Datensatzbeschreibung Bürgermeisterwahlen” extract (bmbm.csv, Stand 26.02.2025). One row per Gemeinde covers the most recent Bürgermeisterwahl in the 7-year Amtszeit window (2019-11-10 through 2026-02-15) with every candidate (up to 15 slots), both rounds’ turnout, and the elected mayor’s identity + party.
• Fallback / supplement: the Landeswahlleiter portal scrape (wahlergebnisse.sachsen-anhalt.de/wahlen/bm{24,25,26}/) is retained for the 5 post-cutoff 2026 elections (Zerbst 12 Apr, Karsdorf 22 Mar, Stößen 29 Mar, Steigra 7 Jun, Teutschenthal 7 Jun) and for one candidate row (Wöhling, Genthin 2024) missing from the StaLA CSV due to a corrupted record.
• All 3 kreisfreie Städte + 16 Große Kreisstädte now have their Oberbürgermeisterwahl on record: Halle (Vogt, 2025), Magdeburg (Borris, 2022), Dessau-Roßlau (Reck, 2021), Merseburg, Wittenberg, Halberstadt, Wernigerode, Sangerhausen, Aschersleben, Bernburg, Stendal, Naumburg, Weißenfels, Zeitz, Quedlinburg, Staßfurt, Schönebeck, Bitterfeld-Wolfen, Köthen.
• The unharmonised dataset (mayoral_unharm) grows 68 → 275 round-results for ST; the candidate-level dataset (mayoral_candidates) grows 168 → 611 rows; the mayor-election panel goes from a handful of ST persons to 220. All ten hand-verified named OB winners (Reck, Vogt, Borris, Buchheim, Müller, Szarata, Kascha, Schweiger, Amme, Ristow) match the official records; Genthin 2024 is fully re-completed via the portal supplement (correct 8-candidate list including Sarah Wöhling, 96 votes).
• Party attribution reflects the formal Wahlvorschlag — in Sachsen-Anhalt it is common for party-affiliated politicians to run as Einzelbewerber without formal party nomination (e.g. Dr. Silvia Ristow — Bernburg OB, 2021 — is a Die Linke member but ran as an Einzelbewerberin, correctly recorded with empty party in the source).

2026-06-27

Baden-Württemberg Landtagswahl 2026 and Kreistagswahl 2024 added. Both come from the Statistisches Landesamt Baden-Württemberg’s official GENESIS regional tables.

• Landtagswahl, 8 March 2026 (state_unharm / state_harm_21 / state_harm_23 / state_harm_25): +1,101 Gemeinden. This was the first BW state election under the new two-vote system (Erst- and Zweitstimme); GERDA records the Zweitstimme (Landeslistenstimme), the proportional list vote, as each party’s vote — the natural continuation of the earlier single-vote series. Turnout 69.6%, and the statewide shares (GRÜNE 30.2%, CDU 29.7%, AfD 18.8%, SPD 5.5%, Linke 4.4%, FDP 4.4%, Freie Wähler 1.9%, BSW 1.4%) reproduce the official final result exactly.
• Kreistagswahl, 9 June 2024 (county_elec_unharm / county_elec_harm_21_cty): +35 Landkreise (the 9 Stadtkreise hold no Kreistag election). Per-party vote shares for all Wahlvorschläge; the BW Kommunalwahl is cumulative (Kumulieren/Panaschieren), so valid_votes counts cast individual votes (30,378,168 statewide). This source has no turnout fields, so eligible_voters / number_voters / invalid_votes / turnout are NA for 2024.
• BW Kreistag local-list series made consistent (2004–2019). The older BW Kreistag tables broke out only the named statewide parties, leaving the large local Wählervereinigungen bloc uncaptured (party shares summed to only ~0.75). That residual local-list share is now assigned to the waehlervereinigungen column for 2004–2019, so shares sum to ~1.0 and the local-list series runs continuously (~22–25%) through to 2024. Named-party shares are unchanged.
• The whole chain was independently re-derived from the raw files and audited raw → unharmonized → harmonized: vote totals are conserved exactly at every stage, no municipalities or counties were dropped, and no other state or year was affected.

2026-06-27

Hessen 2026 municipal & county council elections added. The Gemeindevertretungs- and Kreistagswahlen held on 15 March 2026 in Hessen are now in the council datasets, from the official Landeswahlleiter results portal.

• Municipal councils (municipal_unharm / municipal_harm / municipal_harm_25): +419 Hessen Gemeinden that held a proportional council election (Gemeinden running a majority vote, where no party lists were submitted, are not included), with full party vote shares and turnout. The new BSW is broken out as its own column; local Wählergruppen and minor parties fold into other. Vote shares (including other) sum to exactly 1.
• County councils (county_elec_unharm / county_elec_harm_21_muni / county_elec_harm_21_cty): +415 Hessen Gemeinden (per-Gemeinde Kreistag results) plus 21 Landkreis-level aggregates.
• Hessen’s municipal/county votes are cumulative (Kumulieren/Panaschieren — each voter has as many votes as council seats), so valid_votes counts cast individual votes, not ballots. The extraction reproduces the official portal’s per-party totals exactly (0 mismatches across all 834 Gemeinde results), and the 2021→2026 trends are as expected (e.g. AfD roughly doubling).

2026-06-27

Baden-Württemberg mayoral elections — all-candidate upgrade via Komm.ONE. BW (state 08) now combines two sources instead of one.

• Previously BW was winner-only (the Statistisches Landesamt report B VII 3-j/25 publishes just the elected person). We now add full candidate-level results — every candidate, votes, complete turnout, and both Hauptwahl and Stichwahl — scraped from Komm.ONE’s votemanager portal (wahlergebnisse.komm.one), the result system of BW’s municipal IT provider. 274 BW elections now carry full candidate lists (≈2003–2025).
• It is a hybrid: Komm.ONE supersedes the winner-only record for a municipality’s election only when it published the decisive round (a Stichwahl, or a Hauptwahl won with ≥ 50%); otherwise the Statistical Office’s winner is kept (this matters for the rare runoff that Komm.ONE’s portal omits). BW mayoral candidates still have no party (none is recorded in BW), and the elected winner’s gender + birth year continue to come from the official register (the published count of 114 elected women is preserved exactly).
• The extraction was independently re-verified against the live Komm.ONE API (vote counts, turnout, winners, both rounds) and the result cross-checks the Statistical Office figures (225/226 winner vote counts identical).

2026-06-27

2026 Kommunalwahlen added — Bayern and Hessen. The newest round of local direct elections is now in the mayoral (and, for Bayern, Landrat) datasets.

• Bayern, 8 March 2026 (Stichwahl 22 March): +1,920 Gemeinden (incl. 50 Oberbürgermeister) into the mayoral datasets and 62 Landkreise into the Landrat datasets, from the Bayerisches Landesamt für Statistik official Mandatsträger file. Full candidate-level vote counts and turnout; the elected person’s name, gender, birth year and first date of taking office are included, and the panel links re-elected incumbents to their earlier terms (1,075 of the 2026 winners were already in office).
• Hessen, 15 March 2026 (Stichwahlen 29 March / 12 April, plus January and June by-elections): +28 Gemeinden (incl. the Hanau Oberbürgermeister runoff; 9 Stichwahlen). The ~12 Gemeinden already in the Hessisches Statistisches Landesamt’s May-2026 B VII m Direktwahlen report carry full vote counts; the remaining ~16 (the by-elections and March results not yet in that report issue) are sourced from the official hessenschau result pages as vote-share only (candidate, party, share and turnout). A built-in check guarantees every recorded winner actually won (≥ 50% in the decisive round), and the runoff date is taken from the page text.
• Hessen direct elections — all-candidate upgrade. The whole Hessen mayoral/Landrat dataset (state 06, ~2020–2026) was rebuilt from the Statistical Office’s May-2026 B VII m report in XLSX form, which lists every Wahlvorschlag with its vote count (up to 20 per election) and full turnout — a major upgrade over the previous data, which had only the winner plus the first list. The parser reproduces the official table exactly (0 mismatches across 463 elections).
• All 13 sampled winners across both states were independently re-verified against official municipality pages and local press (13/13 match), including the change of Oberbürgermeister in München (Dominik Krause, Grüne) and Augsburg (Florian Freund, SPD).

2026-06-26

Hessen added to mayoral and Landrat elections — mayoral coverage now spans 13 states.

• mayoral_unharm, mayoral_harm, mayoral_candidates, mayor_panel: +509 Hessen round-results covering the most recent direct Bürgermeister-/Oberbürgermeisterwahl of all 421 Gemeinden (incl. 12 Oberbürgermeister — the 5 kreisfreie Städte plus the Sonderstatusstädte Hanau, Fulda, Gießen, Marburg, Rüsselsheim, Wetzlar and Bad Homburg). landrat_unharm / landrat_candidates: +21 Hessen Landkreise.
• Digitized from the Hessisches Statistisches Landesamt report B VII m – Direktwahlen (Stand 06.05.2024), a most-recent-per-Gemeinde snapshot (election dates ~2017–2024). The report names the elected winner with party and gender and full turnout, plus the first Wahlvorschlag; it does not list every candidate, so the winner’s vote count is published only where the winner is the first Wahlvorschlag (~69% of elections). Many Hessen mayors are independents (no party).
• A sample of winners across Bürgermeister-, Oberbürgermeister- and Landratswahlen was independently re-verified against Hessenschau, municipal websites and Wikipedia (10/10 match). The 15 March 2026 Kommunalwahl is newer than this report issue and will be added once the Statistical Office publishes the updated tables.

2026-06-25

Brandenburg and Sachsen-Anhalt added to mayoral elections — mayoral coverage now spans 12 states.

• mayoral_unharm, mayoral_harm, mayoral_candidates, mayor_panel: +116 Brandenburg round-results (79 Gemeinden) and +75 Sachsen-Anhalt round-results (66 Gemeinden), scraped from the two Landeswahlleiter result portals.
• Brandenburg covers the most recent Bürgermeister-/Oberbürgermeisterwahl of each amtsfreie Gemeinde/Stadt plus the 4 kreisfreie Städte (Brandenburg an der Havel, Cottbus, Frankfurt (Oder), Potsdam) — election dates ~2018–2026. Sachsen-Anhalt covers all Bürgermeister-/Oberbürgermeisterwahlen of 2024–2026. Both portals publish only the current cycle, so neither is a full historical series; Brandenburg’s amtsangehörige Gemeinden (ehrenamtliche Bürgermeister) are not included.
• Unlike Baden-Württemberg, both states publish party affiliation and all candidates (Hauptwahl + Stichwahl), so they populate the full candidate-level dataset; candidate gender is predicted from names. Single-candidate rounds are Ja/Nein votes. Every result page was parsed directly from the official portals, with per-round vote-total integrity checks (sum of candidate votes = valid votes, except single-candidate Ja/Nein rounds).

2026-06-25

Mayoral elections: new flag_superseded column flags non-decisive Bayern rounds.

• mayoral_unharm and mayoral_candidates gain a logical flag_superseded. The Bayern Wahlen seit 1945 source records each annulled or failed-and-repeated election round as its own dated row; these would otherwise stand as completed elections with their own “winner” even though they did not seat a mayor (e.g. Gnotzheim 1993-01-17 at 45.7% — a different list won the valid 1993-03-21 repeat).
• flag_superseded = TRUE marks (A) annulled rounds (Wahlart “… ungültig”) and (B) a Hauptwahl with no absolute majority (winner < 50%) that was not resolved by a Stichwahl and is followed by a repeat Hauptwahl (Neuwahl) within 250 days. Hauptwahlen that were duly won (≥50%) and merely preceded a later by-election are not flagged. Rows are kept, not dropped — filter flag_superseded == FALSE for decisive rounds only. 87 rows flagged in mayoral_unharm, 239 in mayoral_candidates; FALSE for all other states. The mayor_panel already excluded these rounds, so it is unchanged.

2026-06-25

Baden-Württemberg added to mayoral elections — mayoral coverage now spans 10 states.

• mayoral_unharm, mayoral_harm, mayoral_candidates, mayor_panel: +1,244 round-results covering the most recent Bürgermeister-/Oberbürgermeisterwahl in each of the 1,101 Gemeinden as of 31.12.2024 (election dates ~2016–2024). Digitized from the Statistisches Landesamt Baden-Württemberg report Ergebnisse der Bürgermeisterwahlen in Baden-Württemberg (B VII 3-j/25, Tables 13 + 14).
• Oberbürgermeisterwahl vs. Bürgermeisterwahl is classified by AGS (9 Stadtkreise + 96 Große Kreisstädte = 105 Oberbürgermeister-Gemeinden). Gender and birth year of the elected mayor come from the official register; the count of elected women (114, 10.4%) reproduces the Statistical Office’s published figure exactly.
• BW source limitations carried into the data: mayoral candidates in BW have no party affiliation (winner_party is NA); only the elected winner is published (no losing candidates); and the winner’s vote count is reported only for the decisive round (so for the 143 Gemeinden that needed a Neuwahl/Stichwahl the Hauptwahl vote count is NA). Before this release BW mayoral results were not collected centrally — the legal basis (KomWG §39a) only took effect in August 2023.

2026-06-25

Thüringen added to mayoral elections — near-complete municipal coverage. Mayoral elections now cover 9 states.

• mayoral_unharm, mayoral_harm, mayoral_candidates, mayor_panel: +3,978 Thüringen round-results (1994–2026). The Bürgermeisterwahlen of all ~596 Gemeinden (hauptamtlich + ehrenamtlich) were scraped from the Thüringer Landesamt für Statistik database (wahlen.thueringen.de); the 6 kreisfreie-Stadt Oberbürgermeister elections (Erfurt, Gera, Jena, Suhl, Weimar, Eisenach) were parsed from the Landeswahlleitung’s Info/Daten files.
• Note: per § 50 ThürKWO the database redacts candidate personal data, so for the Gemeinde Bürgermeisterwahlen the candidate field holds the Wahlvorschlag (party / Einzelbewerber label) rather than the person’s name; the within-mayor panel therefore tracks only the named subset.
• A stratified sample of 57 elections was independently re-verified against the live source (57/57 match); all rounds satisfy sum(candidate votes) = valid votes.

2026-06-24

Mecklenburg-Vorpommern added to mayoral & Landrat elections. Digitized all 69 LAIV-MV “Direktwahlen” result PDFs (2000–2026) and integrated them into the existing datasets:

• mayoral_unharm, mayoral_harm, mayoral_candidates, mayor_panel: +25 Oberbürgermeister direct elections in the kreisfreie / große Städte (Schwerin, Rostock, Stralsund, Greifswald, Neubrandenburg, Wismar). Mayoral elections now cover 8 states.
• landrat_unharm, landrat_candidates: +43 Landratswahlen across 18 Landkreise (pre- and post-2011 Kreisgebietsreform), bringing the Landrat dataset to 10 states.

Pre-2011 kreisfreie Städte (Greifswald, Neubrandenburg, Stralsund, Wismar) carry their then-current AGS and are correctly harmonized to 2021 municipality boundaries. Every PDF extraction was independently re-read and cross-checked (vote totals, candidates, parties, winners) against the source.

2026-05-06

Mayoral elections: mayoral_unharm, mayoral_harm, mayoral_candidates

• Election-type classification refined for NRW, Bayern, and Saarland.
• 2025 NRW Stichwahl results now included.
• Head-of-county (Landrat) elections split into a separate dataset (see below).

New: Landrat Elections – landrat_unharm, landrat_candidates. Direct-election results for heads of German Landkreise (and Städteregion Aachen, Regionalverband Saarbrücken), 1945–2026, 9 states, 1,659 elections / 3,753 candidate rows.

2026-04-19

State elections: state_unharm, state_harm

• Fixed turnout >100% caused by unallocated Briefwahl (mail-in) votes in Mecklenburg-Vorpommern (1994–2011) and Schleswig-Holstein (2017/2022). Briefwahl votes are now properly allocated to municipalities using Amt-level or Kreis-level mappings from the Gemeindeverzeichnis.
• Improved Brandenburg 1994 OCR extraction with arithmetic validation and self-correction.
• Fixed eligible_voters incorrectly showing 0 instead of NA for Bavaria 1994–2013 (source data lacks turnout information for these years).
• Added turnout safety flags (flag_harm_turnout_above_1) and caps in harmonized data.

2026-04-19

Python package: initial release of gerda on PyPI — lightweight Python loader for GERDA datasets. Source at hhilbig/gerda-py. Mirrors load_gerda_web, gerda_data_list, and party_crosswalk from the R package; covariate / Census merge helpers not yet ported.

2026-04-10

State elections: state_unharm, state_harm

• Fixed Hamburg 2020: replaced Wahlkreislistenstimmen with Landesstimmen (state-wide list votes), consistent with all other Hamburg elections.

2025-11-28

Municipality elections: municipal_unharm, municipal_harm

• Corrected issues in Schleswig-Holstein 1998 and Rhineland-Palatinate 1999 municipal election data

2025-11-21

State elections: state_unharm, state_harm

• Added state election data to include state elections in 2022 (Niedersachsen) and 2023 (Bavaria and Hessen)

2025-11-20

Federal elections: federal_muni_raw, federal_muni_unharm, federal_muni_harm

• Resolved issue in harmonized federal election data at municipality level where some municipalities entered with 0 vote shares for 2021 or 2025 depending on the dataset

2025-10-09

Covariate panel data: ags_area_pop_emp_2023

• Updated covariate panel data to period 1990-2023

2025-07-31

Federal elections: federal_cty_unharm, federal_cty_harm

• Removed minor error: Berlin was sometimes duplicated due to two different county ags. Now aggregated to one ags for Berlin for each election year

2025-05-20

Federal elections

• Updated federal election datasets to include 2025 elections
• Create two versions of the harmonized panel:
  • 2021 borders: All elections (1990-2025) mapped to 2021 municipality boundaries
  • 2025 borders: All elections (1990-2025) mapped to 2025 municipality boundaries
• Created our own crosswalks based on official crosswalking data from the BBSR

2025-04-22

Federal and state elections

• Added election dates for federal and state elections based on election type and date combinations

2025-04-14

Publication of database on Nature: Scientific Data