The mathematics of election

Archbishops, police commissioners, presidents and prime ministers. Elections designed to choose a candidate as fairly as possible occur all over the world. Last week Barack Obama was re-elected for a second term as the 44th President of the United States of America. The race to sit in the Oval Office at the White House, becoming one of the most powerful figures in the world, started over a year ago. Primary elections of candidates from different parties resulted in the whittling down of the hopefuls to just two men.

The fiercely fought campaign was surrounded by speculation and a large amount of calculations. Graphs, coloured maps and even games monitoring progress and predicting the outcome of the election have been as ubiquitous as placards and slogans. The people behind the maths are known as ‘pollsters’. A pollster takes a particular sample of public opinion in order to create a representative model of public opinion at large. Based on these calculations, the relative progress of candidates on the road to election is measured.

However, the pollsters are not always right. As the Twig film The Wrong Guy Won (log in required) highlights, the 1936 American presidential election is often remembered for an embarrassingly skewed use of sample polling as much as for its actual result. As in all mathematical systems, the sample must be considered carefully in order to avoid bias, accounting for demographics within it and margin of error.  This year the opinion polls were close to the end result but as always, it’s not over until it’s over.