Just to cut to the chase: researchers sent letters to more than 190 members of Congress, asking for a meeting. When they introduced themselves as donors, they were more than five times more likely to get the meeting than when donations weren't mentioned. And those meetings were usually with more senior staffers.

That's from a study conducted by researchers from Yale and Berkeley aimed at determining if political donations increased access to elected officials. The answer was clear: it does.

The set-up was simple. Working with the progressive group CREDO Action, Yale's Joshua Kalla and Berkeley's David Broockman wrote emails asking members of Congress for a meeting. On a third of the emails, the letter requested the meeting on behalf of "active political donors;" on the other two-thirds, the request was for a meeting with local constituents. And:

When it was constituents asking, the people in the meeting got to meet mostly with lower-ranked district staff. (The meetings actually happened, by the way, without the participants knowing how they'd been scheduled.) When it was donors, members of Congress were more likely to provide heavy hitters. Donors, for example, were four times more likely to get to meet with the member of Congress directly. 

It's hard to overemphasize the importance of what this study suggests. It's often suggested that members of Congress vote on issues in response to donations they've received. That's not how it works in practice. We've noted before that politicians primarily respond to personal influence when making decisions. Donations buy face time, not votes. What donors have always bought with their money is the promise of access, precisely as suggested in today's study. ExxonMobil (and CREDO) don't get votes with donations. They get meetings.

As The Washington Post notes, the researchers think that their research only scratches the surface.

Broockman said he was surprised by the size of the difference, and noted that the study may actually underestimate the access of political donors, since none of the offices were told ahead of time the identities of the contributors, how much they had given – or even whether they had donated to that member of Congress.

Imagine a big lobbyist who's given thousands of dollars over multiple cycles, knows the Congressman, and sends an email inviting him to join a foursome at a prestigious golf club. Think that guy is likely to get a meeting? And if he does, what do you suppose they'll talk about?