Different Process, Same Outcome? The Problems of Within-Party Sortition

A recent article in Political Quarterly argues for a ‘sortition of candidature’. We show that because political parties are not themselves socially representative, such a scheme would not result in a socially representative Parliament. Drawing on data from the Party Members Project, we show that while some demographic groups would be better represented than at present under within-party sortition, in other ways, things would become less representative. This conclusion holds under a range of possible election outcomes. For this type of sortition to generate a descriptively representative House of Commons, we would need to see a significant influx of new party members from currently under-represented groups. This seems to be very unlikely, based on what we know about the public's appetite for political engagement. We conclude that while this proposal might not make things much worse, it is unlikely to make them much better.