Dataset for "The decline of Duverger? The impact of evolution on party systems in the United Kingdom"

A complete dataset of elecion results to the Welsh Assembly/Senedd, Northern Ireland Assembly and Scottish Parliament, as well as general election results in Wales, Scotland and Northern Ireland since 1997. It includes all constituency results, including constituency level results from the regional lists of Scottish and Welsh AMS elections. This dataset includes turnout rates at the constituency level and includes measures of strategic voting in each constituency including the margin of victory, the third placed parties distance from contention and the effective number of parties.