ESS Election Dates

The European Social Survey (ESS) prompts respondents' to recall their vote choice in the most recent national election. As the ESS is a pan-European bienniel social survey whose fieldwork periods do not follow electoral calendars (unlike European or national election studies), this can result in some challenges for comparative voting research across electoral contexts:

1. Several consecutive ESS rounds may record respondents' voting behavior in one and the same election. In Belgium, for example, ESS Rounds 7 (fieldwork period: 2014-09-16 to 2015-02-01), 8 (2016-09-15 to 2017-01-31) and 9 (2018-09-20 to 2019-01-27) all record vote choices in the general election of 2014-05-25.
2. The vote choice question in ESS rounds may be split if a national election takes places during the ESS fieldwork period. For instance, the 2012 Dutch general election took place on 2012-09-12, thus splitting Round 6 (fieldwork period: 2012-08-30 to 2013-03-29). The Dutch Round 6 questionnaire specifically asks for respondents' vote recall in the general election of September 2012. However, 257 respondents were interviewed before election day and the data includes vote choice information for these respondents (presumably their vote choice in the previous general election of 2010).

In order to address research questions that require information on the political, socio-economic, or temporal contexts under which individuals cast their votes (studying, e.g., the effects of parties' position taking, issue salience in electoral campaigns, or pre-/post-differences after crises or critical events), it is important that users accurately match ESS vote choice data with the correct election dates.

ESS Election Dates allows users to do this by simply matching election dates to ESS country-waves using the ESS' cntry and essround identifiers. In the case of split rounds, users must additionally use the idiosyncratic interview dates, captured by a combination of the variables inwyr-inwmm-inwdd (year/month/day of interview, ESS Rounds 1 + 2), inwyys-inwmms-inwdds (year/month/day of interview start, ESS Rounds 3-9), or inwyye-inwmme-inwdde (year/month/day of interview end, ESS Rounds 3-9).

Used together with Sophie E. Hill's updated ESS-Partyfacts Crosswalk, this resource will allow users to quickly combine ESS vote choice data with party, election, and party-election specific variables for most countries across Rounds 1-9. Election dates were taken from ParlGov, thus coverage is contingent on the inclusion of countries in the ParlGov data base.

Codebook

Variable	Description
cntry	ISO2C country code (as used in ESS)
essround	ESS Round
field_start	Start date of first interview in each country-wave
field_end	Start date of last interview in each country-wave
recent_election	Date of the most recent election
max_days_since_election	Number of days between most recent election and last interview
split_wave	General election during fieldwork period (TRUE/FALSE)
recent_election_split1	Date of the most recent election for respondents interviewed before election day in a split wave
max_days_since_election_split1	Number of days between the last election and the last pre-election interview in a split wave