  This paper is a corrigendum and addendum to the previously published article:
'How Populist are Parties? Measuring Degrees of Populism in Party Manifestos
Using Supervised Machine Learning' (Political Analysis, 1-17.
doi:10.1017/pan.2021.29). These corrigendum and addendum were prepared to
correct errors in data labelling and show some extra insights not included in
the previously published paper. Here, we report these corrections and point to
some additional conclusions by focusing on the effects of the label reshuffling
per parties and years and presenting new figures wherever appropriate. We show
that although the simplified labelling method proposed in the
previously-published article can induce biases in the correlations with expert
scores, random labelling reduces correlations significantly. We show that this
is also true for correlations based on a manually-coded data set. These
modifications are based on other evidence and results reported in detail in a
future publication.
