NBER Working Papers · 2026 · Joshua S. Gans
中文摘要
当人工智能提供商的服务既可用于攻击又可用于防御时，提供商应承担多大责任？责任可能在增加损害的同时改善福利。提供商向生产性用户、攻击者和防御者出售一种共同投入品。在存在防御的攻防博弈中，更高的共同投入品价格会降低努力水平，而不改变攻击成功率或攻击者利润，从而节约资源并改善目标的安全收益。赔偿会削弱防御并提高攻击者利润。最优责任需要在这些效应与生产性用户被排除在服务使用之外所造成的损失之间进行权衡。竞争加剧可能降低最优责任；每一次此类下降都必须止于仍保留防御的结果。在网络安全服务接入情况给定时，垄断可能使部分责任具有合理性，但只要提供服务是值得的，完全责任就绝不会具有合理性。当存在能够保留生产性用途的护栏时，强竞争会使所有提供商均设置护栏在社会层面更为有利，但在责任不足时又会激励提供商单方面移除护栏。在提供商数量给定时，足够多的生产性用户可确保在高责任水平下存在所有提供商均设置护栏的纯策略均衡。要求所有提供商均设置护栏，会使责任不再必要。在垄断下，护栏的采纳由唯一的责任阈值决定；而当生产性用户足够多时，在一定参数范围内，零责任仍是唯一最优选择。
Abstract
How much liability should AI providers bear when their services enable both attack and defence? Liability can improve welfare while increasing harm. Providers sell a common input to productive users, attackers and defenders. Within a defended contest, a higher common price reduces effort without changing attack success or attacker profits, saving resources and improving the target's security payoff. Compensation weakens defence and raises attacker profits. Optimal liability balances these effects against productive exclusion. Greater competition can lower optimal liability; every such decline must end at an outcome retaining defence. With cybersecurity access fixed, monopoly can warrant partial liability but never full liability when provision is worthwhile. When guardrails preserving productive uses are available, strong competition favours universal guarding socially but encourages unilateral removal at insufficient liability. At a fixed provider count, sufficiently many productive users ensure a pure equilibrium with universal guarding under high liability. A universal-guarding requirement makes liability redundant. Under monopoly, adoption follows a unique liability threshold, while zero liability remains uniquely optimal for a range of parameters with sufficiently many productive users.