SC Connecticut News

Social scientists have long acknowledged the "friendship paradox," a phenomenon where individuals' friends tend to have more connections than they do. While this might affect self-esteem, it presents opportunities for marketers and public health officials to maximize outreach efforts.

Yale School of Management's Vineet Kumar has conducted research on identifying highly connected individuals within networks without needing full network data. This work explores mathematical principles behind the friendship paradox and introduces methods to utilize this principle in both online and real-world networks for various campaigns.

Kumar, an associate professor of marketing, focuses on technology's impact on business and society. His research suggests that using his approach can be more effective in controlling infections or promoting products compared to other seeding strategies.

The study titled “On the Friendship Paradox and Inversity: A Network Property with Applications to Privacy-sensitive Network Interventions” examines inversity, which assesses the similarity or dissimilarity between connected nodes based on their number of friends. Co-authors include Scott Feld from Purdue University and David Krackhardt from Carnegie Mellon University.

Two methods for intervention seeding are proposed: the ego-based strategy involves selecting a friend of a random network individual as the target; while the alter-based strategy is novel, asking individuals for contact information of multiple friends at a chosen rate. Both strategies outperform existing methods like random selection or relying on network leaders.

In epidemic models, immunizing 25% of a network using these strategies could prevent an outbreak, whereas random interventions might require 50% coverage. These approaches emphasize privacy sensitivity by not requiring extensive knowledge about network structures or members.

Kumar notes additional factors like equity should be considered in public health campaigns but highlights the relevance of the friendship paradox in enhancing performance across networks. He further investigates these methods' applications in other areas with colleague K. Sudhir, finding potential improvements over previous opinion leader approaches in spreading microfinance awareness in rural India.

The implications extend to marketing, public health, politics, and misinformation tracking within networks using these privacy-sensitive interventions.

"The idea applies very broadly to any network and application," Kumar explains. "The people that are more popular—and therefore more effective in seeding interventions—are more likely to be reached using the friendship paradox."

These findings underscore simple yet impactful strategies that can be deployed across diverse applications while maintaining privacy considerations.