Do party system parameters explain differences in legislative organization? : Fragmentation, polarization, and the density of regulation in European parliaments, 1945–2009

The article studies whether the party system characteristics fragmentation and ideological polarization increase the density of institutional regulation in parliaments. It introduces a comprehensive time-series-cross-sectional dataset of standing orders in 15 Western European parliaments that allows studying how densely various fields of legislative activity such as lawmaking, controlling the government, and creating publicity were regulated over a period of more than 60 years. Descriptively, the data show increased regulation in all areas but also some variation between countries. Dynamic panel regression analyses for non-stationary time series find no systematic effect of fragmentation or polarization on the density of regulation indicating that large parts of legislative organization change for reasons unrelated to party system dynamics. We identify changes in the environment of legislatures such as increasing complexity and professionalization of politics, technological change, and Europeanization as potential drivers of such Pareto-efficient reforms.