ALIGN: Aligned Delegation with Performance Guarantees for Multi-Agent LLM Reasoning
Tong Zhu, Baiting Chen, Jin Zhou, Hua Zhou, Sriram Sankararaman, Xiaowu Dai
TL;DR
ALIGN reframes LLM reasoning as an aligned delegation game where a principal relies on multiple agent LLMs to generate diverse candidates and selects the best via ranking feedback. The method leverages online mirror descent with negative entropy to update agent policies, yielding sublinear regret and convergence to a Nash equilibrium under fair comparison and positive alignment assumptions. Theoretical guarantees show that, with equal access to candidates, multi-agent delegation improves principal utility over single-agent generation, and empirical results across GSM8K, MATH, and GSM-Hard demonstrate robust improvements over strong baselines. The framework is training-free and robust to principal choice, highlighting practical impact for robust, scalable, and provably better reasoning with LLM ensembles. The work also identifies conditions under which alignment is necessary and demonstrates empirical validation of these conditions.
Abstract
LLMs often underperform on complex reasoning tasks when relying on a single generation-and-selection pipeline. Inference-time ensemble methods can improve performance by sampling diverse reasoning paths or aggregating multiple candidate answers, but they typically treat candidates independently and provide no formal guarantees that ensembling improves reasoning quality. We propose a novel method, Aligned Delegation for Multi-Agent LLM Reasoning (ALIGN), which formulates LLM reasoning as an aligned delegation game. In ALIGN, a principal delegates a task to multiple agents that generate candidate solutions under designed incentives, and then selects among their outputs to produce a final answer. This formulation induces structured interaction among agents while preserving alignment between agent and principal objectives. We establish theoretical guarantees showing that, under a fair comparison with equal access to candidate solutions, ALIGN provably improves expected performance over single-agent generation. Our analysis accommodates correlated candidate answers and relaxes independence assumptions that are commonly used in prior work. Empirical results across a broad range of LLM reasoning benchmarks consistently demonstrate that ALIGN outperforms strong single-agent and ensemble baselines.
