It’s long been said that money opens doors in the political world, and a new study (pdf) confirms this axiom.

Two graduate students, Joshua Kalla at Yale University and David Broockman at UC Berkeley, decided to send letters to 191 members of Congress asking for a meeting to discuss legislation banning a certain chemical.

With the help of the grassroots progressive group CREDO Action, the letters went out with only two variations: one batch indicated the person requesting the meeting was a constituent, and the other batch came from those professing to be a donor.

Guess which group received more meetings? Donors, by a difference of about 5%.

Another interesting discovery was the disparity between donors and constituents really went up when the meetings took place with the lawmaker or their chief of staff.

Members of Congress were four times more likely to meet with donors than constituents, and their chiefs of staff were five times more likely. Overall, access to senior staffers tripled for donors.

“We were certainly surprised by our results,” Kalla told The Huffington Post. “The magnitude of the difference between really just changing one word—constituent to donors—in two spots in an email, had a pretty massive impact in being able to meet with a senior congressional official.”

Kalla, Broockman and CREDO were motivated to do this research by the U.S. Supreme Court’s rationale in the controversial Citizens United (pdf) case. In that ruling, the justices said the lifting of campaign contribution restrictions for corporations and unions would not leave the average voter at a disadvantage in the political process.

“We were dismayed to see the Supreme Court decision in the Citizens United case, and particularly the fact that it was based in part on the fact that they suggested there was no evidence that there was any corrupting evidence of federal campaign donations on the political process. So this study is so exciting because it’s the first scientifically based evidence that we’ve seen that there is a real link between campaign donations and federal policy,” CREDO Political Director Becky Bond said.

-Noel Brinkerhoff

To Learn More:

Lawmakers More Likely To Meet With Campaign Donors Than Constituents, New Study Finds (by Amanda Terkel, Huffington Post)

Congressional Officials Grant Access Due To Campaign Contributions: A Randomized Field Experiment (by Joshua Kalla and David Broockman, UC Berkeley) (pdf)

Every Member of Congress Elected in 2012 Received Money from at least one of the 31,385 Biggest Donors (by Matt Bewig, AllGov)

This Year, Lockheed Donated to Election Campaigns of 386 of 435 Members of House of Representatives  (by Noel Brinkerhoff, AllGov)