Too big to run? Analysing the impact of enlargement on the speed of EU decision-making

The article analyses how enlargements affect the speed of European Union (EU) decision-making. In line with rationalist theories of group choice, we argue that enlargements increase the costs of organizing decisions, i.e. transaction costs. Increasing transaction costs, in turn, slow down EU law-making. We test this theory by estimating Cox regression models that incorporate time-varying covariates on all directives, regulations and decisions submitted by the European Commission between 1976 and 2006. In contrast to previous analyses, we show that an increase in group size indeed slows down EU law-making.