Decentralization has an important geographic dimension that conventional metrics, such as stake distribution, often overlook. Where validators operate affects resilience to regional shocks (e.g., outages, natural disasters, or government intervention) as well as fairness in reward access. Yet in permissionless systems, validator locations cannot be prescribed by protocol rules; instead, they emerge endogenously from economic incentives. When certain locations offer systematic advantages, validators may strategically co-locate to maximize expected rewards, as observed in Ethereum, where validators cluster along the Atlantic corridor, which exhibits structurally favorable latency. In this paper, we design and implement an agent-based simulation framework to study how Ethereum's protocol design, particularly its block-building paradigms of local and external block building, interacts with validator and information-source distributions to shape geographical positioning incentives. Our simulations show that Ethereum's block-building architecture is not geographically neutral: both paradigms induce location-dependent payoffs and migration incentives, with asymmetric access to information sources amplifying geographical centralization. We further demonstrate that consensus parameters, such as attestation thresholds and slot times, modulate latency sensitivity and can amplify these effects, acting as protocol-level levers. Finally, we discuss the implications of our findings for protocol design and outline potential mitigation directions informed by our analysis.

翻译：去中心化具有重要的地理维度，而传统指标（如权益分布）往往忽视了这一点。验证者运营的位置影响着系统对区域冲击（例如，服务中断、自然灾害或政府干预）的弹性，以及奖励获取的公平性。然而，在无需许可的系统中，验证者的位置无法通过协议规则规定；相反，它们从经济激励中内生地形成。当某些位置提供系统性优势时，验证者可能会策略性地共置以最大化预期收益，正如在以太坊中观察到的现象：验证者聚集在大西洋走廊沿线，该区域在结构上具有有利的网络延迟。在本文中，我们设计并实现了一个基于智能体的模拟框架，用以研究以太坊的协议设计（特别是其本地和外部区块构建范式）如何与验证者及信息源的分布相互作用，从而塑造地理定位激励。我们的模拟表明，以太坊的区块构建架构在地理上并非中性：两种范式都会导致与位置相关的收益和迁移激励，而对信息源的不对称访问则加剧了地理集中化。我们进一步证明，共识参数（如证明阈值和时隙时间）可以调节延迟敏感性，并可能放大这些效应，充当协议层面的杠杆。最后，我们讨论了研究结果对协议设计的影响，并基于我们的分析概述了潜在的缓解方向。