CODEBOOK Political Data Yearbook

Version 1.0 (Jan 2024) Raul Gomez, Thomas Mustillo, Michelangelo Vercesi (Editors of the Political Data Yearbook)

Suggested citation: Gomez, Raul, Mustillo, Thomas. and Vercesi, Michelangelo.(2025). Political Data Yearbook Codebook. Available at https://politicaldatayearbook.com/ (Accessed: DD MM YY).

INTRODUCTION

This codebook guides PDY contributors on operationalising variables and populating the data templates. While we aimed to maintain consistency with the criteria used by our contributors in previous years, the codebook’s systematic implementation only began in January 2024. Consequently, some decisions made previously by certain authors might diverge from these rules.

OPERATIONALISATION AND NOTES

1. ELECTIONS

Lower house elections are reported for all countries. Upper house elections are reported only for Australia, Czech Republic, Japan, Italy, Netherlands, France, Poland, Romania, Spain, Switzerland, United States. European Parliament elections are reported for EU member states.

Party: includes any political party that obtained at least 1% of the national share of votes in the parliamentary election.

‘Others’ is a category comprising all parties that obtained less than 1% of the vote.

The sum of all the votes obtained by parties and independent candidates (including ‘Others’ ) must sum to the total votes cast. If they do not, include a note about the reasons for the discrepancy.

Independent candidates (those not affiliated with or officially sponsored by any party) are normally included in the ‘Others’ category. However, if the combined support of independent candidates is at least 1% of the popular vote, create a separate category called ‘independents’.

Vote

Vote %: percentage of valid votes obtained by each party at national level. If the electoral system is mixed (e.g., both proportional and plurality with two ballots), report the proportional vote.

Use ‘Others’ for the combined vote share of parties and independent candidates that obtained less than 1% of the vote individually.

The sum of all the votes obtained by parties (including ‘Others’ ) must sum to the total votes cast. If they do not, include a note about the reasons for the discrepancy.

Include all independent candidates under ‘Others’ unless a separate ‘independents’ category exists (see Party).

Vote N: Number of votes obtained by each party at national level. If the electoral system is mixed (e.g., both proportional and plurality with two ballots), report the proportional vote.

Use ‘Others’ for the combined number of votes obtained by parties with less than 1% of the vote individually.

The sum of all the votes obtained by parties (including ‘Others’ ) must sum to the total votes cast. If they do not, include a note about the reasons for the discrepancy.

Include all independent candidates under ‘Others’ unless a separate ‘independents’ category exists (see Party).

Seats N: Total number of seats obtained by each party in the corresponding chamber.

Use ‘Others’ for the combined number of votes obtained by parties that obtained less than 1% of the vote individually.

Include all independent candidates under ‘Others’ unless a separate ‘independents’ category exists (see Party).

Δ%: difference in percentages relative to the year before (for example, from 3% in 2021 to 5% in 2022 = +2%); note that this is not calculated using absolute numbers.

2. RESULTS OF REGIONAL ELECTIONS

Regional election results are only reported for the following federal countries: Austria, Belgium, and Germany. For Spain, regional elections for the most populated regions are usually reported in detail. These include the Community of Madrid, Catalonia, Andalusia, and the Valencian Community.

For other countries, regional elections may be discussed in the text within the relevant section. If one or more regional/state elections are considered to be significant enough (e.g., in federal or devolved countries) these may be introduced as tables, but, please, check with the editors if you intend to do so.

Party: includes any party list that obtained at least 1% of the vote share in the relevant region.

Others’ is a category comprising all parties that obtained less than 1% of the vote.

Independent candidates will normally be included in the ‘Others’ category. However, if the combined support of independent candidates is at least 1% of the popular vote in the corresponding region, then create a separate category called ‘independents’.

Vote %: percentage of valid votes obtained by each party at regional level.

If the electoral system is mixed (e.g., both proportional and plurality with two ballots), report the proportional vote.

Use ‘Others’ for the combined vote share of parties and independent candidates that obtained less than 1% of the vote individually.

The sum of all the votes obtained by parties (including ‘others’) must sum to the total votes cast. If they do not, include a note about the reasons for the discrepancy.

Include all independent candidates under ‘Others’ unless a separate ‘independents’ category exists (see Party).

Vote N: Number of votes obtained by each party at regional level.

If the electoral system is mixed (e.g., both proportional and plurality with two ballots), report the proportional vote.

Use ‘Others’ for the combined number of votes obtained by parties with less than 1% of the vote individually.

Include all independent candidates under ‘Others’ unless a separate ‘independents’ category exists (see Party).

Seats N: Total number of seats obtained by each party in the regional legislative chamber.

Use ‘Others’ for the combined number of votes obtained by parties with less than 1% of the vote individually.

Include all independent candidates under ‘Others’ unless a separate ‘independents’ category exists (see Party).

3. REFERENDUM

Unless there is a specific reason (you may want to check with the editors) you only need to include country-wide referendums.

Referendum question: include the exact wording of the question asked in the referendum in both English and the original language/s (if different).

Valid answers: include the exact wording (or its translation, if not in English) of the options given in the referendum.

N: Number of votes received by each of the valid answer options.

The sum of all the votes obtained by each option must sum to the total votes cast. If they do not, include a note about the reasons for the discrepancy.

Vote %: Percentage of valid votes obtained by each answer option.

The sum of all the votes obtained by each option must sum to the total votes cast. If they do not, include a note about the reasons for the discrepancy.

4. EXISTING CABINET/NEW CABINET

New cabinet: a cabinet is considered ‘new’ if there has been a change of PM (or President in Presidential systems), a change in the composition of the cabinet, and/or a new general election.

Any meaningful resignation or new ‘swearing in’ define a new cabinet.

Please use these criteria even if they diverge from the criteria used in the country to name cabinets, but add a note if that is the case.

Dissolution date: date of exit from office (in parliamentary systems, the date of resignation or loss of parliamentary confidence, if applicable, can be indicated in the main text).

Type of cabinet: this is merely defined by the number of parliamentary seats of the parties that have ministers in the cabinet. It does not include parties that are only represented through junior ministers or that provide external support to the cabinet (e.g., via a confidence-and-supply agreement), but such cases can be indicated via footnotes.

If one or more ministers belong to parties that do not have parliamentary representation, please indicate that in a footnote but count them as partisan.

If the cabinet can be defined as a caretaker cabinet, (i.e., appointed as a ‘bridge’ between cabinets with full ‘authority to make major policy initiatives’ [Golder 2010: 4] and which is not expected to change substantially the status quo), please specify that in a footnote or in the main text.

Criteria for classifying the type of cabinet:

• SPMA (single-party majority): one party in government with more than 50% of seats in the first chamber; 
• SPMI (single-party minority): one party in government with 50% or less of seats in the first chamber; 
• MWC (minimum winning coalition): coalition with more than 50% of seats in the first chamber, but where the removal of the smallest party would take it at or below 50%; 
• OC (oversized coalition): coalition with more than 50% of seats in the first chamber, where not all parties are necessary to have more than 50%; 
• MC (minority coalition): coalition with 50% or less of seats in the first chamber; 
• NP (non-partisan): cabinet where the majority of ministers are not party members, do not have a party affiliation, and/or are not selected as party representatives by the party they belong to. If the percentage of partisan ministers is exactly 50%, the cabinet is non-partisan if the finance minister is non-partisan (McDonnell and Valbruzzi 2014); 
• Not applicable: only for countries where the cabinet is not accountable to the legislature: Cyprus and the US (presidential systems) and Switzerland (directorial system). 

When two electorally distinct parties form a single parliamentary group (e.g., German CDU and CSU), they are considered as one party in order to define the type of cabinet. However, they should be treated separately when counting the number of ministers for each party.

The former does not apply to ‘mixed’ parliamentary groups, for which only the MPs from the relevant party should be considered.

Seats in parliament: indicate the number of seats held in the first chamber by each of the parties present in the cabinet.

For bicameral countries, if a party is represented only in the second chamber this can be added as a note but should not be included in the main table or taken into account when defining the type of cabinet.

Comments on single ministerial changes (if any):

• Reason: i.e., resignation; replaced; moved to another position; cabinet reshuffle. If the ‘comment’ is longer than three lines, please include additional information in a note or in the main text;

• Incoming date: date when the minister was appointed (only if it does not coincide with the outgoing date of the previous minister).

5. PARLIAMENT

Party: includes all parliamentary party groups, including mixed groups (if applicable) and independent/unaffiliated MPs (if any).

Please include any new parties entering parliament as a result of an election or a party change (split, merge, etc.). You may use a footnote to add more information about the new party.

Women %: refers to the percentage of women relative to the total number of MPs in the relevant party.

Notes

If there is substantial change during the year (e.g., a general election), please fill in the tables for 1 January, the date when the change took place, and 31 December.

Except in highly unusual circumstances, the figures for parliamentary membership by gender and party in the previous year’s Yearbook for 31 December will be the same as those for this year’s Yearbook on 1 January, so feel free to copy those cells over to the new template.

Upper House

Data for the upper house of parliament must only be reported for the following bicameral countries: Australia, Czech Republic, France, Japan, Italy, Netherlands, Poland, Romania, Spain, Switzerland, United States.

For other bicameral countries the table is optional, but relevant changes in the composition of the upper house must be discussed in the main text of the Political Data Yearbook.

6. CHANGES IN POLITICAL PARTIES

Party: this includes parties represented in parliament (first and/or second chamber) during the year under investigation, as well as those that entered parliament in the following year and those that are likely to enter parliament in the future (based, for example, on opinion polls).

Regarding splinters, please include only those that remain in parliament (first and/or second chamber) or are likely to remain or become relevant parties (i.e., return to parliament) according to your expert opinion.

For splits, please indicate the name of the original party as well as the name of the two or more new parties. For mergers, please indicate the names of all merging parties.

References

Golder, Sona N. (2010). ‘Bargaining delays in the government formation process.’ Comparative Political Studies, 43(1), 3-32.

McDonnell, Duncan and Marco Valbruzzi (2014). ‘Defining and Classifying Technocrat-Led and Technocratic Governments.’ European Journal of Political Research 53(4): 654-671.