Splitting the Local and Regional Vote

Voting at local and regional elections open up for inter-level split ticket voting. But who cast a split vote and who cast a straight vote at the sub-national elections? And do the patterns vary between local and regional elections? In this paper the empirical data originates from the Danish local election survey conducted right after the 2017 local elections in Denmark but the paper seeks to go into the more general question of how the patterns of inter-level split voting differs at the local and the regional level - is it the same voters who split their votes between national and regional elections as the ones who votes for different parties at the national and the local elections? And whom among the electorate chooses to cast a local/regional split vote?