Node-based Generalized Friendship Paradox fails

TL;DR

This paper demonstrates that the node-based version of the Generalized Friendship Paradox can fail depending on network structure, challenging assumptions about attribute correlations in social networks.

Contribution

It provides the first analysis showing the failure of the node-based Generalized Friendship Paradox and explores conditions affecting its validity.

Findings

Node-based paradox can fail even with high degree-attribute correlation.

Network structure influences the validity of the node-based paradox.

Both positive and negative results are established regarding the paradox's applicability.

Abstract

The Friendship Paradox--the principle that "your friends have more friends than you do"--is a combinatorial fact about degrees in a graph; but given that many web-based social activities are correlated with a user's degree, this fact has been taken more broadly to suggest the empirical principle that "your friends are also more active than you are." This Generalized Friendship Paradox, the notion that any attribute positively correlated with degree obeys the Friendship Paradox, has been established mathematically in a network-level version that essentially aggregates uniformly over all the edges of a network. Here we show, however, that the natural node-based version of the Generalized Friendship Paradox--which aggregates over nodes, not edges--may fail, even for degree-attribute correlations approaching 1. Whether this version holds depends not only on degree-attribute correlations, but also on the underlying network structure and thus can't be said to be a universal phenomenon. We establish both positive and negative results for this node-based version of the Generalized Friendship Paradox and consider its implications for social-network data.