The Issue-index model provided an updated prediction of the election result. The model expects that Clinton will achieve 55.4% of the two-party vote share, whereas Trump will win 44.6%. In comparison, on August 7 Trump was still predicted to win 44.7% of the vote.
Putting the results in context
As any other method, index models are subject to bias. In general, you should not rely too much on the results of an individual index model. At least, one should check how a index model's results compare to benchmark forecasts.
Results in comparison to other index models
In comparison to the average results of other index models Clinton performed better with 1.6 percentage points, while Trump did worse with 1.6 percentage points.
The Issue-index model compared with PollyVote's prediction
Clinton has 2.7 percentage points more and Trump has 2.7 percentage points less when the results of the index model are compared to the combined PollyVote forecast.