Polling best election predictor despite Trump win: study

Polling is still the best predictor of election outcomes globally, despite the surprise victory of US President Donald Trump who was widely predicted to lose the 2016 elections to Hillary Clinton, a new study suggests.
Trump's election as President was viewed by some people as evidence that electoral polling no longer works, but researchers at University of Houston in the US have developed models using global polling data that can correctly predict up to 90 per cent of election outcomes around the world.
The study focused on executive elections in which voters cast ballots directly for the person who will hold executive office, rather than having that leader elected by parliament.

Researchers said it offers strong evidence that polling data used correctly is best predictor of election outcomes.
"This study suggests polling data can be utilised not just in the US but globally to predict election outcomes," said political scientist Ryan Kennedy from University of Houston.
"It would be a mistake to abandon the enterprise. The future really is in trying to make better quantitative predictions," said Kennedy.

Researchers submitted forecasts two weeks prior to elections in Latin America in 2013 and 2014 and correctly forecast the winners in 10 out of 11 elections, or 90.9 per cent of the time.

A second test, involving live predictions for all global direct executive elections starting in mid-2013, had a success rate of 80.5 per cent, researchers said.
The model was developed using election dataset covering over 500 elections in 86 countries, along with a separate dataset that incorporated polling data from 146 elections.
Researchers discovered that economic growth had little impact on election outcomes.
"Less democratic institutions, unsurprisingly, tended to favour the incumbent party," researchers said.
Kennedy said open democratic elections and whether one candidate was an incumbent improved the likelihood of accurate predictions.
However, he said the most valuable predictor proved to be polling results, something that proved true across the globe.

"People normally would not find this surprising. But given the recent (US presidential) election, now it does seem surprising," he said.
"Where there was a poll, it was reasonably good at predicting outcomes, even in places you would not think you would be able to have accurate polling," Kennedy said.
The researchers said their findings are especially salient in light of Trump's victory, which prompted predictions of the death of data and polling.
Kennedy noted that he and his collaborators predicted an 84 per cent chance of a Clinton victory.
"That meant a 16 per cent chance of a Trump victory. Unlikely but still possible," he said.

"We often think anything over 50 per cent means absolutely an outcome is going to happen. That is not necessarily the case," Kennedy said.
The study was published in the journal Science.