Introduction
This paper is a summary of analysis conducted of an international database of 31,310 polls from 473 elections and voting events across 40 countries around the world from 1936 through to 2017 compiled by Kantar.
When examined at a global level polls are generally very accurate, the average error of polls conducted within seven days before an election is +/-2.5%.
The aim of this paper, though, is to help you understand why there can be differences in the size of errors seen in different types of election in different countries around the world and to educate on the things...