March 30, 2017

Social networks on Capitol Hill influence legislation, funding

The old adage, “it’s not what you know, it’s who you know” has long fueled the parental drive for children to attend Ivy League schools. But it turns out where you went to school is less important than who else went to the same school – at least, if you’re in Congress.

It’s no surprise that legislative success is correlated with friendship networks: Vote for my bill, I’ll vote for yours. But a new working paper by Cornell economists Marco Battaglini and Eleonora Patacchini, “Influencing Connected Legislators,” shows that even the amount of campaign contributions received by legislators is linked to their social networks in Congress.

“There is a long tradition of political scientists talking about how social connections among legislators are important in the way laws are drafted and in the success of politicians,” said Battaglini, the Edward H. Meyer Professor of Economics in the College of Arts and Sciences. “If this is true – that the vote of person J influences the vote of person Y – then we should expect that interest groups and lobbyists would pay attention to this network of connections.”

To determine what role networks play, Battaglini and Patacchini mapped social networks using alumni connections among members of Congress at the undergraduate and graduate/professional school levels. Since most legislators went to more than one school, the network was complicated.

“Our theory gave us a precise way to measure centrality in this complex context,” said Patacchini, professor of economics. “Then the task was to take that and apply it to the data, measuring the network connections and the money to try to see the connections.”

Traditionally, literature about interest groups’ influence on Congress assume that legislators are entirely self-interested, but this “ignores deep connections of friendship, respect and patronage that transcend partisan or ideological divisions,” write the researchers. “If interpersonal relations truly play a role in legislators’ behavior, then we should expect them to play a role in how interest groups allocate resources among legislators.”

According to the economists’ theory, the money allocated to a legislator should be proportional to his or her centrality in the social network. And that is precisely what the researchers found. Using data on the last five U.S. Congresses, they found a statistically significant connection between the legislators’ centrality in the social network and the money that they received from political action committees (PACs).

“We find that the allocation of the interest groups’ moneys is generally a complex function of the voting function, the legislators’ preferences for the policy and the geometry of the social network,” said Battaglini.

The extensive data set the researchers used allowed them to look at other correlations as well, such as links between legislators proportional to their number of shared committees. In a related project, Battaglini and Patacchini are exploring how effective legislators are at promoting legislation is correlated with alumni connections. “The idea is that the more you are connected, the more you can convince other legislators to support whatever legislation you are trying to promote,” explained Battaglini.

Linda B. Glaser is a staff writer for the College of Arts and Sciences.