The CSES Dataset

The Comparative Study of Electoral Systems (CSES) project provides a comparative dataset of election studies and is created by an international team of researchers from around the world. The national research teams include a common set of questions in the national post-elections surveys, such as the British Election Study. This data is combined with electoral variables, demographics, district and national level variables and information on the respective political system. One key advantage of the dataset is that it combines the election studies of a wide range of countries into one single data file and ensures that a considerable number of important questions are asked across these countries in a consistent manner.

A core set of questions remains the same in every survey, but the CSES also incorporates new research topics in its questionnaire, with every of the five-year waves of data collection focusing on a different topic. For instance, the fifth iteration of the project, runs from 2016 to 2021 and is called “Democracy Divided? People, Politicians and the Politics of Populism.”. The subsequent module has specific questions on the topic of “Representative Democracy under Pressure”. Each module comprises a different set of countries, driven, among other aspects by the cooperation of a local team to ensure that a post-election survey is run and the CSES questions are included. Some countries, such as the USA, Germany and Sweden are included in all five modules. The dataset can be accessed here. We present the dataset below. At the end of the presentation, we provide a link to a platform with an interactive version of the dataset and additional tasks.

Dataset Description

Micro-Level Data

The CSES dataset provides data for respondents on three different levels: micro-level (demographic) data, micro-level (survey) data, district level data and macro-level data. Table 1 shows ten randomly drawn respodents from the dataset. Besides the variables shown here, CSES provides data on occupation, race, income, immigration and region/electoral district.

Table 1 Example from the Austria dataset

	Year of Birth	Gender	Education	Religion	Country
18114	1960	2	99	1208	Iceland
20973	1940	2	6	1101	Italy
12599	1975	2	7	1600	Greece
11468	1927	2	3	1101	France
10636	1998	1	7	1101	France
19824	1972	2	7	1101	Italy
9805	1981	2	4	1101	France
12512	1971	1	6	1600	Greece
34065	1938	1	8	1200	United States of America
1049	1984	2	4	8300	Australia

Table 2 shows an example of the voting data in the survey section of the dataset. For each of the major party, the survey asks for their left-right self-placement, their perceived placement of the parties on the left-right scale, and how much they like or dislike the parties. Then, it asked for voting decisions in the most recent parliamentary and presidential election, both on the party as well as the district level.

Table 2 Example of voting questions from the German dataset

	Vote Choice - Party	Left-Right Self-placement	Left-Right CDU	Left-Right SPD	Left-Right Linke	Left-Right Gruene	Left-Right CSU	Left-Right FDP	Left-Right AfD	Like-Dislike CDU	Like-Dislike SPD	Like-Dislike Linke	Like-Dislike Gruene	Like-Dislike CSU	Like-Dislike FDP	Like-Dislike AfD
7710	other	7	8	6	3	2	9	7	10	9	4	2	7	9	9	0
7711	SPD	4	5	4	2	4	5	5	10	7	8	5	8	5	5	0
7713	other	6	7	5	1	5	7	6	10	10	7	1	8	10	8	0
7714	Gruene	3	7	2	0	3	9	5	10	3	6	5	8	2	4	0
7715	SPD	2	5	2	0	3	7	7	10	4	9	6	8	2	3	0
7716	FDP	5	5	3	0	5	7	5	10	2	2	3	1	3	6	1
7717	SPD	8	1	1	2	1	1	0	8	6	6	5	5	4	5	7
7718	other	4	3	4	1	5	3	6	10	9	8	5	7	7	5	0
7719	SPD	4	5	4	2	4	7	3	10	10	10	7	8	0	8	0
7720	other	3	6	3	3	4	6	8	10	9	10	9	8	10	7	0

In addition to the qustions on voting, the CSES includes a battery of questions in all national post-election surveys that follow a certain theme. In wave 5, this theme is centered around populism. Consequently, Table 3 shows some of the questions on populism from the survey: The respondents were asked to strongly agree, somewhat agree, neither agree not disagree, somewhat disagree or strongly disagree with statements on political elites. In the table, higher values indicate more disagreement with the respective statement.

Table 3 Example of substantive questions from the German dataset

	Vote Choice - Party	Elites: Compromise Selling Out	Elites: Do Not Care	Elites: Trustworthy	Elites: Main Problem	Elites: Strong Leader	Elites: People Make Decisions	Elites: Rich and Powerful
7710	other	2	4	4	3	4	1	2
7711	SPD	3	4	3	4	5	3	4
7713	other	3	4	1	5	2	4	5
7714	Gruene	5	4	2	5	5	5	3
7715	SPD	4	2	3	3	5	1	2
7716	FDP	5	4	1	5	5	3	5
7717	SPD	3	2	3	3	3	3	1
7718	other	3	3	3	4	5	2	3
7719	SPD	3	3	3	3	5	1	3
7720	other	5	5	2	5	5	5	3

District-Level Data

On the district level, the CSES dataset matches district-level results to the place of residence of the respondent. Table 4 shows an example from Germany. In mixed-systems such as Germany, the CSES always reports the district level vote share in this section, which corresponds to the vote for the district candidate in Germany.

Table 4 Example of district level data from the German dataset

	Electoral District	District Vote Share CDU	E5001_A	District Vote Share SPD	District Vote Share AfD	District Vote Share FDP	District Vote Share Linke	District Vote Share Gruene	District Vote Share CSU
9684	189	38.01	26.76	14.30	21.40	4.89	15.28	2.56	999
8682	282	39.40	26.76	21.07	9.60	8.70	5.04	14.95	999
9061	79	35.37	26.76	24.56	8.16	9.06	7.51	12.73	999
9166	57	30.58	26.76	19.43	20.18	3.80	18.45	3.69	999
9414	166	34.99	26.76	11.07	25.95	5.58	15.54	3.77	999
9163	57	30.58	26.76	19.43	20.18	3.80	18.45	3.69	999
8351	175	36.42	26.76	28.31	14.85	6.13	5.89	5.41	999
9530	154	34.06	26.76	11.46	28.66	6.32	15.60	3.91	999
7787	22	29.74	26.76	34.58	9.49	7.03	9.17	7.09	999
9253	60	31.79	26.76	25.08	16.94	4.58	15.13	3.41	999

Macro-Level Data

On a macro-level, the dataset provides information on electoral results on the national level (votes and seats) for lower and upper houses as well as presidential elections. In the dataset, some countries had parliamentary elections included in the dataset, some presidential, and some both. Table 5 shows 10 individual respondents from the main dataset and the elecotral results that were matched based on the coutnry they live in.

Table 5 Example of macro level electoral data from the CSES dataset

	Country	Vote Party A	Vote Party B	Seats Party A	Seats Party B	Vote President A	Vote President B	Turnout
24642	Montenegro	41.41	20.32	44.44	22.22	997.00	997.00	73.41
21349	Republic of Korea	38.33	37.00	40.67	41.00	997.00	997.00	58.15
14520	Hungary	49.27	19.06	66.83	13.07	997.00	997.00	69.73
12310	Greece	35.45	28.08	48.33	25.00	997.00	997.00	56.16
13719	Hungary	49.27	19.06	66.83	13.07	997.00	997.00	69.73
16677	Iceland	29.00	15.90	33.33	15.87	997.00	997.00	79.18
31860	United States of America	999.00	999.00	44.60	55.40	48.18	46.09	63.83
425	Australia	36.66	33.34	44.37	45.03	996.00	996.00	91.89
22618	Lithuania	22.63	22.45	21.99	38.30	997.00	997.00	50.64
332	Australia	36.66	33.34	44.37	45.03	996.00	996.00	91.89

Table 6 shows some of the data that is available on the party level: Parties are coded by party experts into party families, on the left-right scale and in relation to populism. Additionally, the dataset includes information on whether parties were in parliament, in government and what share of government offices they held.

Table 6 Example of macro level party data from the CSES dataset

	Country	Portfolios Before Election Party A	Portfolios Before Election Party B	Portfolios After Election Party A	Portfolios After Election Party B	Ideological Family Party A	Ideological Family Party B
34611	United States of America	999	999	999	999	6	9
3576	Brazil	5	0	2	0	9	4
30049	Taiwan	0	41	43	0	98	98
22419	Republic of Korea	19	0	19	0	7	4
2905	Austria	5	7	6	0	8	4
9303	Germany	7	6	7	6	8	4
27325	New Zealand	20	0	0	16	9	4
10110	France	0	0	2	0	6	10
12288	Greece	31	0	28	0	5	9
6761	Chile	0	0	5	5	9	9

Additionally, the dataset contains a multitude of variables describing the electoral system, such as whether there is compulsory voting, whether there are party thresholds or which voting system (e.g. party lists, single member districts,…) is used. An of the CSES dataset is that all data is available in one dataset so researchers can combine individual-level survey data and macro-level information in a coherent manner.