With great accuracy in the past several election cycles, Campbell has developed what he calls the convention bump model. Much like a meteorologist forecasts the weather based on current conditions, Campbell takes the second quarter GDP numbers and combines them with a measure of presidential popularity before and after the political conventions.
His conclusion: President Obama will win the election with 51.3 % of the national popular vote in November .
"In this case we sort of have a battle of the two variables. The economy clearly works this time in favor of Mitt Romney but incumbency and the public's pre disposition seem to favor President Obama and that gives him a slight edge.," Campbell says, adding that Mitt Romney still could win depending on the economy and the electoral college.
|We're not asking who you WANT to win, but who you honestly THINK will win...|
|( 39% )|
|( 61% )|
Related: Both sides have different philosophies in the messages they feel need to be sent to win the presidential election in November. READ MORE
Campbell's model has a strong track record, correctly reflecting or predicting the outcome in all but two presidential elections since Harry Truman's. He didn't get Nixon's victory in 1968, and Campbell admits that the timing of his forecast-- after the convention -- still leaves room for economic catastrophe to come in and change his results, as it did last year.
During the last election cycle, he says no one could account for the late season economic meltdown, therefore he forecast a John Mc Cain victory with 52.7 percent of the vote. His forecast does not look at state-by-state numbers and as such could also be trumped by an electoral college decision that goes against the popular vote.
"Forecasts are always wrong, it is a matter of the degree of error and you know it's not unusual for the forecast to be about 2 points off either way. That still beats the polls available ," he says .
"I'm about 67 percent sure that President Obama will get 50 percent of the vote, but there's still a third of a chance that Governor Romney can pull this out.
Campbell's model is one of approx. 13 different formulas used by political scientists to determine election out come. This year for the first time he has taken his numbers and those of 13 colleagues and averaged them together (See BELOW) for a universal forecast, showing President Obama with an average 50.3 percent of the vote.
A similar Reuters survey of nine forecasts-- including Campbell's-- put the average Obama victory at 50.5 percent of the popular vote. In 2008, the Reuters survey of the same group forecast 52 percent for Obama and 48 percent for Republican John McCain -- which " was about as close to the election results as Gallup's final poll from the last three days of the presidential campaign," Reuters wrote.
|RELATED: Campbell redicts that the Democrats can expect to lose 51 seats in the House of Representatives in the November election, producing a Republican majority. From UB, READ MORE|
From Larry Sabato's Crystal Ball Blog
at the Center for Politics at the University of Virginia
Forecasting the Presidential Election: Other Crystal Balls
Most of us spend our campaign days eagerly devouring the latest public opinion polls, and there is no shortage of them. In the six days after the conclusion of the party conventions (through Wednesday afternoon), there have been three major national polls released — not including daily tracking surveys by Gallup, Rasmussen and Reuters/Ipsos — and 13 state-level surveys; RealClearPolitics lists 57 national polls since June 1. But polls are not predictive. As the pollsters always say, each poll is just a snapshot of an object moving in time. Moreover, the further one gets away from the actual election day, the more misleading polls can be, because it is difficult to figure out who will actually show up to vote, and many events that might influence the horserace (such as debates or crises) have not yet occurred.
A better way to forecast the election results — potentially, at least — is to uncover the underlying fundamentals that propel an electorate to vote the way it does, and to combine them in some rigorous, standard fashion based on America’s voting history. Quite a number of political scientists have done so, creating models that use statistical techniques such as regression analysis — seeing how one variable, like the economy, affects another, like an election outcome — to predict presidential elections. A model should ideally be simple and elegant, using relatively few variables and constants to generate a forecast.
Prof. James Campbell of the University at Buffalo, SUNY has gathered together 13 models’ forecasts for a symposium to be published in the October edition of PS: Political Science & Politics (a journal of the American Political Science Association).
With his permission, we are giving our readers a sneak peek at these forecasts, some of which are based on national data and others of which rely on state-level information. As the table shows, they vary widely, with eight of the 13 showing victory for President Obama and five seeing Mitt Romney as the next president. The chances of an Obama plurality range from a mere 10% to a definitive 88%. For whatever it is worth, the average of the models’ projected vote for President Obama (of the two-party total, excluding third-party and independent candidates) is 50.2% — a tiny advantage for Obama, but hardly ironclad. By comparison, Obama won 53.7% of the two-party vote in 2008, and 52.9% of the total popular vote (including votes cast for third-party candidates).
Crystal Ball readers may remember Campbell’s piece for us from last month, which laid out how the bleak economy threatened Obama’s chances. However, it’s worth noting that despite the poor economy, his Convention Bump Model shows Obama getting 51.3% of the two-party vote. We have also featured the model from Crystal Ball Senior Columnist Alan Abramowitz this summer; his Time for Change Model, with its strong record of accuracy, shows Obama getting 50.6%. (His percentage is also the median Obama vote among the 13 models.)
You’ll have to wait for the Campbell PS symposium, which will be online in a few weeks, to see the details and discussion of the individual models, and of course the election results will enable all of us to see which models were more correct.
Chart 1: Selected 2012 presidential election models