Item-side Fairness of Large Language Model-based Recommendation System

TL;DR

This paper investigates item-side fairness in Large Language Model-based Recommendation Systems, identifies influencing factors, and proposes a framework called IFairLRS to improve fairness, demonstrated through fine-tuning LLaMA on MovieLens and Steam datasets.

Contribution

It introduces the first comprehensive analysis of item-side fairness in LRS and develops a novel framework, IFairLRS, to enhance fairness in these systems.

Findings

Significant fairness improvements achieved with IFairLRS

Item bias influenced by user interactions and semantic biases of LLMs

Framework adaptable to different datasets and LLMs

Abstract

Recommendation systems for Web content distribution intricately connect to the information access and exposure opportunities for vulnerable populations. The emergence of Large Language Models-based Recommendation System (LRS) may introduce additional societal challenges to recommendation systems due to the inherent biases in Large Language Models (LLMs). From the perspective of item-side fairness, there remains a lack of comprehensive investigation into the item-side fairness of LRS given the unique characteristics of LRS compared to conventional recommendation systems. To bridge this gap, this study examines the property of LRS with respect to item-side fairness and reveals the influencing factors of both historical users' interactions and inherent semantic biases of LLMs, shedding light on the need to extend conventional item-side fairness methods for LRS. Towards this goal, we develop a concise and effective framework called IFairLRS to enhance the item-side fairness of an LRS. IFairLRS covers the main stages of building an LRS with specifically adapted strategies to calibrate the recommendations of LRS. We utilize IFairLRS to fine-tune LLaMA, a representative LLM, on \textit{MovieLens} and \textit{Steam} datasets, and observe significant item-side fairness improvements. The code can be found in https://github.com/JiangM-C/IFairLRS.git.