The limitations of opinion polls – and why this matters for political decision making

Recent research by Jennings and Wlezien has demonstrated that political polling has remained as accurate as ever in terms of margin of error in the week prior to an election. However, polls are usually publicly judged on whether they call the result correctly. In this, writes Sean Swan, they have been less accurate over recent UK elections. This has particular consequences for how and when political leaders make decisions about discretionary elections, and so it matters that we understand polls and their limitations correctly.