Fairshare Data Pricing via Data Valuation for Large Language Models
Luyang Zhang, Cathy Jiao, Beibei Li, Chenyan Xiong
TL;DR
This work addresses fair data pricing for LLMs by framing the data market as a Stackelberg game where buyers and sellers exchange datasets valued by their contribution to model performance. It introduces fairshare pricing, derived from data valuation signals, to sustain seller participation and maximize long-term buyer utility, contrasting it with exploitative pricing that destabilizes the data supply. Theoretical analyses show exploitative pricing leads to market collapse, while fairshare pricing yields a mutually beneficial equilibrium. Empirical simulations across NLP tasks demonstrate higher seller profits, stable data supply, and improved buyers’ cost-efficiency, with robustness to various valuation methods. The approach offers a practical blueprint for transparent, equitable, and economically sustainable LLM data markets, with implications for policy and platform design.
Abstract
Training data is the backbone of large language models (LLMs), yet today's data markets often operate under exploitative pricing -- sourcing data from marginalized groups with little pay or recognition. This paper introduces a theoretical framework for LLM data markets, modeling the strategic interactions between buyers (LLM builders) and sellers (human annotators). We begin with theoretical and empirical analysis showing how exploitative pricing drives high-quality sellers out of the market, degrading data quality and long-term model performance. Then we introduce fairshare, a pricing mechanism grounded in data valuation that quantifies each data's contribution. It aligns incentives by sustaining seller participation and optimizing utility for both buyers and sellers. Theoretically, we show that fairshare yields mutually optimal outcomes: maximizing long-term buyer utility and seller profit while sustaining market participation. Empirically when training open-source LLMs on complex NLP tasks, including math problems, medical diagnosis, and physical reasoning, fairshare boosts seller earnings and ensures a stable supply of high-quality data, while improving buyers' performance-per-dollar and long-term welfare. Our findings offer a concrete path toward fair, transparent, and economically sustainable data markets for LLM.
