Economy, economy, economy.

That has been the spine of Mitt Romney's campaign. Even as other issues flare up, Romney is banking on the fact that widespread dissatisfaction with a sluggish economic recovery will make this a referendum on President Obama (for example, his advisers say they are steering clear of a debate over abortion provoked by Missouri Senate candidate Todd Akin's controversial remarks).

Conservative critics ranging from Wisconsin Governor Scott Walker to the Wall Street Journal editorial page have questioned the Romney campaign's narrow approach, warning that he must offer a sweeping vision rather than count on an up-or-down vote on the Obama economy.

But a new study by two University of Colorado professors seems to vindicate Romney's strategy. Using a model that incorporates state-level economic data, Kenneth Bickers and Michael Berry predict that Romney will notch a resounding 300 electoral votes -- far more than the 270 needed -- while capturing 52.9 percent of the popular vote.

It's a counterintuitive finding to be sure. Most analysts predict a narrow outcome to this election, with national polls showing Romney and Obama in a virtual dead heat and both camps formulating paths to get the coveted 270, from Karl Rove's 3-2-1 route to the Obama camp's Western strategy

And by focusing exclusively on indicators like unemployment figures and trends in per capita income, Bickers and Berry minimize the importance of other policy debates -- for example, now that Mitt Romney's selection of Rep. Paul Ryan as his running mate has intensified focus on Ryan's plan to overhaul Medicare, voters in three swing states say by wide margins they trust Obama more to oversee Medicare.

But the University of Colorado professors note that their model, drawing on more than two decades of data, would have accurately picked a winner for the last eight presidential elections. They said the economy would be an overriding factor, with Berry noting in a press release that "the apparent advantage of being a Democratic candidate and holding the White House disappears when the national unemployment rate hits 5.6 percent," compared to its current rate of 8.3 percent.

Voters also experience the economy differently depending on where they were situated. Bickers and Berry found that voters link unemployment rates to Democrats but hold Republicans responsible for income changes.

"What remains to be seen is whether voters will consider the economy in relative or absolute terms," Berry said in a press release. "If it's the former, the president may receive credit for the economy's trajectory and win a second term. In the latter case, Romney should pick up a number of states Obama won in 2008." 

The study will be published in PS: Political Science & Politics, a peer-reviewed journal of the American Political Science Association.