The Impact of Incumbent/Opposition Status and Ideological Similitude on Emotions in Political Manifestos
Takumi Nishi
TL;DR
The paper investigates how incumbency status and ideological similarity influence emotion-laden language in UK party manifestos (Conservative and Labour) from 2001–2019. It employs VADER and EmoLex lexicon-based sentiment analysis on 12 manifestos, with text extraction via pdfminer.six and NLP preprocessing to quantify positive/negative language and eight basic emotions. The study finds that incumbents tend to use more positive language while opposition uses more negative language, and ideologically similar parties emphasize positive language, though Labour's 2017–2019 leftward shift introduces more negative lexicons, underscoring contextual political dynamics. These findings advance understanding of manifesto strategy and political persuasion and demonstrate a scalable methodology for longitudinal political-text analysis.
Abstract
The study involved the analysis of emotion-associated language in the UK Conservative and Labour party general election manifestos between 2000 to 2019. While previous research have shown a general correlation between ideological positioning and overlap of public policies, there are still conflicting results in matters of sentiments in such manifestos. Using new data, we present how valence level can be swayed by party status within government with incumbent parties presenting a higher frequency in positive emotion-associated words while negative emotion-associated words are more prevalent in opposition parties. We also demonstrate that parties with ideological similitude use positive language prominently further adding to the literature on the relationship between sentiments and party status.