AI 中文总结
本文研究生成式AI降低专家服务信号成本导致的市场混同问题，提出结果依赖型责任信号可恢复市场分离，还内生化合同制度并设计了相关验证实验。
AI 中文摘要
生成式人工智能已将生成令人信服的专业成果——报告、分析、提案——的成本降至几乎为零。信号理论预测，那些信息内容依赖生产成本的信号，在生产成本变得低廉时会丧失其信息内容。我们针对作为信任品市场的专家服务市场，将生成式AI建模为压缩了机器以可忽略成本生成的成果与买家可区分成果之间的可辨别空间，来形式化这一预测。在某一临界空间以下，生产侧信号不存在分离均衡；市场会出现混同，高能力提供者无法获得溢价，拥有外部选择权的提供者会退出，形成阿克洛夫的柠檬市场动态。我们证明，一种结果依赖型信号——带有事后可验证性φ且赔偿金额为D的保证——只要φ*D≥v（v为解决问题的价值），就能在任何AI能力水平下恢复完全分离。责任的预期成本取决于问题是否得到解决，而非文件生产成本。一个推论表明，来源认证（如C2PA）因成本与类型无关，无法恢复分离。基于主体的蒙特卡洛模拟阐释了这些动态。另外两个结果将合同制度内生化：民事诉讼成本设定了最小交易规模v_min，低于该规模则不存在可信的执行威胁；在责任保险下，分离取决于保留风险或风险费率。我们给出了可证伪条件，并提出一项预先注册的、基于选择的联合实验，实验对象为德语区B2B专家服务市场的决策者。
英文摘要
Generative artificial intelligence has reduced the cost of producing convincing artifacts of expertise-reports, analyses, proposals-to nearly zero. Signaling theory predicts that signals whose content rests on production cost lose it when production becomes cheap. We formalize this for expert services, a class of credence goods, by modeling AI as a compression of the discernible headroom between what machines produce at negligible cost and what buyers can distinguish. Below a critical headroom no separating equilibrium in production-side signals exists; the market pools, high-competence providers earn no premium, and those with outside options exit-Akerlof's lemons dynamic. An outcome-contingent signal-a warranty backed by damages D with ex-post verifiability phi-restores full separation at any level of AI capability whenever phi*D >= v, the value of a solved problem, under four preconditions stated explicitly and priced in turn: no seller-side private information beyond type; verifiable collectible retention behind the promise; no buyer influence on outcome or claim; negligible enforcement deadweight. Expected liability cost depends on whether the problem is solved, not on production costs. A further proposition shows that provenance certification priced as a type-independent stamp (e.g., C2PA) cannot restore full separation, while a verified commitment to forgo the AI frontier re-imposes the pre-AI artifact cost function. Two results endogenize contract institutions: civil-procedure costs set a minimum ticket size v_min below which the modeled court-enforced warranty cannot sustain separation; under liability insurance the signal-effective quantity is the retained, collectible exposure. We state falsification conditions and propose a preregistered conjoint experiment with German-speaking B2B decision-makers; the estimand is willingness to pay in excess of the promise's actuarial value.
Comments39 pages, 7 figures. JEL codes: D82, D86, L15, L84, M31, O33. Simulation code and numerical results available at: https://doi.org/10.6084/m9.figshare.33106946
