Projected National Share

Projected National Share (PNS) is a statistic used in British politics. It refers to the translation of local election results into an estimation of the national levels of support that each party would have received had the local elections been taking place across the whole country and with each of the significant political parties standing candidates everywhere. PNS shows which party has ‘won’ any given annual local election cycle (in terms of achieving the highest projected share of the national vote). It also enables psephologists and political commentators to compare the performances of the main political parties (by their projected national shares of the vote) across different years and different local election cycles. This is helpful and important, given that local elections take place in different parts of the country each year; in some years the bulk of the contests can be taking place in the ‘Tory shires’, whereas in other years the local contests can be taking place predominantly in cities and metropolitan areas that have traditionally favoured the Labour Party. The numbers give an impression of how the political parties would have fared if the entire country had been casting a local ballot. PNS can be calculated in different ways.

History

BBC News has calculated PNS since 1982. They use key wards which are reflective of the country as a whole in order to calculate party share. Two academics at the University of Plymouth, Colin Rallings and Michael Thrasher, calculate National Equivalent share (NEV) using a different approach.

Author and peer Mark Pack maintains a historical record named LocalBase of both sets of results.

By local election

*Independents, residents associations and minor parties