RNC Gave Romney Negative Bounce
The Princeton Election Consortium shows that the Republican National Convention was helpful–to Obama.
…the GOP convention was of no help to them in the Electoral College. Indeed, it appears that the race shifted towards President Obama by 6-15 EV, or about 1.0% of Popular Vote Meta-Margin. From an analytical perspective, a negative bounce is quite remarkable because all the talk in recent weeks has been of bounces being smaller or zero, but always in the hosting party’s favor. It is all the more remarkable because of the relatively small number of state polls over the last week, so that the Meta-analysis’s inputs have not fully turned over (for discussion see comments). So the negative bounce may be larger than what is shown in the graph. Such an event would have been missed in past years (and even this year) because national polls don’t have the best resolution.