中文摘要
我估计了一个贝叶斯说服模型,以考察经济激励与不对称信息如何塑造医患互动。这一方法为保险的作用提供了新的洞见。第一,模型预测患者的共同保险会调节医生对服务费上调的反应程度。该预测得到了双重差分分析的支持,该分析使用中国医疗保险理赔数据,其中医生的报销比例和患者的共同保险比例存在随机变异。第二,模型意味着更低的共同保险比例既降低了患者的价格弹性,也降低了其怀疑心理,从而提高了医生误导患者接受不必要治疗的可能性。利用结构模型的估计结果,我表明:对于手术治疗属可自主决定的诊断,在接受手术的患者中,近一半人在完全知情的情况下本不会接受手术。当共同保险比例降低时,医生的这种误导更大,这凸显出道德风险之外的一条新的低效率渠道。我将降低共同保险比例的效应分解为道德风险与新出现的更大误导效应。反事实分析表明,虽然患者受益于更低的自付费用,但更大的误导几乎抵消了这些福利收益。
Abstract
ABSTRACT I estimate a Bayesian persuasion model to examine how financial incentives and asymmetric information shape physician–patient interactions. This approach offers new insights into the role of insurance. First, the model predicts that patients' coinsurance moderates physicians' responsiveness to increases in service fees. This prediction is supported by a difference‐in‐differences analysis using Chinese health insurance claims data with random variation in physicians' reimbursement and patients' coinsurance rates. Second, the model implies that lower coinsurance rates reduce both patient price elasticity and skepticism, increasing the likelihood of physicians misdirecting patients toward unnecessary treatments. Using structural model estimates, I show that for a diagnosis where surgical treatment is discretionary, nearly half of the patients who received surgery would not have done so were they fully informed. Such misdirection from physicians is greater when coinsurance rates decrease, highlighting a new inefficiency channel beyond moral hazard. I decompose the effect of lowering coinsurance into moral hazard and the novel greater misdirection effect. Counterfactual analysis shows that, while patients benefit from lower out‐of‐pocket costs, greater misdirection nearly offsets these welfare gains.