The researchers say that in the 2008 election, swing state results would have changed dramatically without the influence of the mortgage credit crisis. (Associated Press)

The phrase “it’s the economy, stupid” has been repeated countless times since James Carville, an adviser to President Bill Clinton, uttered it during the 1992 presidential campaign. While economic conditions certainly affect voter behavior, a recent study by scholars at the Columbia Business School found a more specific connection between money and voting.

An analysis of presidential elections between 1996 and 2012 found that the availability of mortgage credit is a critical indicator in presidential races and has five times as much impact on voter behavior as rising unemployment. The study, “Mortgage Market Credit Conditions and U.S. Presidential Elections,” by Columbia professor Charles W. Calomiris, co-written with Adonis Antoniades of the National University of Singapore, includes a county-by-county analysis of the 2008 presidential election just as the United States was heading into the Great Recession.

Their research found that while consumers hold the president and his party accountable when credit markets are tight and mortgages are less available, incumbents during periods when mortgages are more widely available don’t reap any electoral benefits.

The researchers say that in the 2008 election, swing state results would have changed dramatically without the influence of the mortgage credit crisis. Specifically, they found that half the votes needed (51 percent) to reverse the election outcome in nine swing states would have gone to Sen. John McCain (R-Ariz.) instead of to then-Sen. Barack Obama (D-Ill.) if not for the contraction in mortgage credit that occurred between 2004 and 2008.

Yet between 2000 and 2004, a period when mortgage credit availability expanded, the researchers didn’t find any evidence that President George W. Bush or the Republican Party received any extra votes.

Voters don’t always reward politicians for a boom in local credit supply but are quick to punish them when credit is less available, Calomiris wrote.