The Politics of Deceit: Analyzing Accusations of Lying in 30 Years of Parliamentary Discourse

The subject of political lying has attracted considerable scholarly attention in recent years. Due to the rise and electoral success of populist politicians, many have diagnosed a so-called post-truth era. While these are strong claims with both a magnitude and a longitudinal dimension, they have seldom been tested systematically, at scale, over long periods of time. By studying accusations of lying in parliamentary debates across 22 countries over a period of three decades, this paper offers a first look at political lying at this scale. We build and analyze the DEMO-LIES dataset, a corpus of 493,053 accusations of lying, uttered by 34,381 speakers for whom we collect biographical and party-level information. Our findings reveal that, globally, accusations of lying have remained stable over the past three decades. We do, however, find considerable cross-country variation, with some countries seeing a rise in accusations of lying, others remaining stable, and yet others experiencing a decline. At both the individual and the party level, we find that populists accuse others of lying more often and are themselves accused more often. Female politicians, by contrast, accuse others of lying less often and are also accused less often. Accusing someone of lying increases the likelihood of being accused by that same person in return, and, similarly, membership in a governing party leads to receiving more accusations. Education and age, however, predict neither accusing nor being accused, and while ideology has a modest, counterintuitive effect on who accuses others, it has no bearing at all on who gets accused.