An election projection uses survey statistics to predict the outcomes of elections. There are a number of statistical methods for doing this. Projections can be based on pre-campaigning surveys, polls during campaigns and exit polls on voting day. Later projections can be made using partial results. An election projection can also form an important part of election monitoring.
Pre-campaign and campaign surveys attempt to test the mood of a nation or locality where an election is about to take place. Surveys and polls ask electors for their opinions on candidates, their likelihood to vote and who they would vote for. If results were taken literally from a single survey, they would not reflect reality. This is why such poll data is adjusted to take into account demographics and voting history.
As a campaign builds, more and more polls will be conducted in voting areas. Using statistical techniques, the results of the surveys can be used to project who will win in the elections. These take into account the likelihood of one party’s voters turning out to vote, cross-party appeal of certain candidates and intra-party hostility against the party’s own candidate.
Voting intentions are often weighed based on the voting system in place. For example, American Presidential election polls need to factor in the Electoral College system in an election projection. That means if candidate A is projected to get 51 percent of votes in every state, he or she will get more than 51 percent of electoral votes. In fact, he or she would get about 535 of the actual votes compared to three for candidate B. This is because all states give 100 percent of their electoral votes to the winner with only Maine and Nebraska using proportional voting.
Exit polls are surveys taken of people who have voted. Exit poll results are not announced until after voting stations have closed. While there is no guarantee that voters tell pollsters the truth, it is usually a good indication of the actual result. When mixed with partial results from the first constituencies or states to declare, a better picture can be created of the national mood. For example, in 2010, Labour in England held on to its traditional seats, but each result showed a massive swing against the party; this led to an election projection of a change in government, as Labour would lose more marginal seats.
Election monitors in countries all over the world are generally looking for free and fair elections. They seek to weed out corruption and vote rigging. The election projection is important to this because it allows monitors to survey voters and to make projections on two fronts: the total number of voters and who they voted for. Sophisticated election projections can then be compared to the actual declared result.