MIND THE GAP A Quantitative Study of Parliamentary Mandate Gaps and Executive Aggrandizement in Europe

Abstract

This study examines how parliamentary power concentration affects democratic quality in Europe. I argue that existing explanations that focus on economic factors, democratic consolidation and ideological preferences do not fully capture the reasons behind the ongoing trend of democratic backsliding in Europe. Instead, this study suggests that incumbents need the opportunity to engage in executive aggrandizement and that mandate gaps, defined as the difference in seat share between the incumbent and largest opposition party, have potential to create such opportunity structures by weakening legislative oversight. Using panel data from 41 European countries from 2008 to 2022, this study shows that mandate gaps are associated with a decline in V-Dem’s Liberal Democracy Index (LDI). Furthermore, analyses of LDI’s sub-indices show that mandate gaps negatively affect both electoral and liberal dimensions of democracy. Additionally, the results show a negative effect of large mandate gaps on the index measuring legislative constraints on the executive, which aligns with this study’s theoretical mechanisms.