What is the poll.graphics nowcast?
A nowcast is not a prediction or forecast for a future election, but a hypothetical projection for the here and now. The word is a blend of “now” and “forecast”. More on the definition of the term here (European Central Bank, 2013).
The poll.graphics nowcast is a projection for the here and now that combines past election data with current polling figures. It can be read as follows: what would happen if today’s voters behaved like the voters at the last election – but voted the way the current polls measure?
To calculate winning probabilities, we also use the poll.graphics nowcast in Monte Carlo simulations. More on the concept.
An important caveat: people change. New voters join the electorate (naturalisations, young people reaching voting age), others leave it (emigration, death and so on). In short, the electorate changes.
The poll.graphics nowcast therefore claims neither to forecast future voting behaviour nor to replace opinion polls, which can give a more accurate picture of how people actually vote today.
You will find various analyses of our nowcasts on our blog.