互惠性偏好视角下医患委托代理模型研究

Doctor-Patient Principal-Agent Model under Reciprocity Preference Theory

委托代理关系脆弱是造成医患矛盾的重要原因。为了解决医生道德风险,结合“医保一体化”的思想,将患者医药费负效用与医生工资挂钩,建立了委托代理模型。分析发现:工资制度中的激励系数越大,医生的努力程度越高。不同风险偏好组合下最佳激励系数具有差异。内化的医药费在很大程度上规避了“以药养医”的道德风险。在此基础上,将Rabin提出的互惠性偏好理论引入模型,研究互惠性视角下的医患交易激励机制设计。结果表明:当患者支付给医生的固定费用大于其所能支付的最高固定费用的一半,且医生付出的努力程度大于其最大努力程度的一半时,医患双方具有互惠行为,此时双方收益均高于完全理性时的收益。同时,患者支付医生的固定费用越高,医生的努力程度就越高。最后,通过数值模拟对比完全理性和互惠性偏好下双方的收益可以得出,互惠性偏好下患者和医生的收益存在帕累托改进。

The weak principal-agent relationship is the root cause of the tension between doctors and patients.To solve the moral hazard of doctors,a principal-agent model was established to link the disutility of patients’medical expenses with doctors’salaries by drawing on the idea of“medical insurance integration”.It is found that the greater the incentive coefficient in the salary system,the higher the efforts of doctors.The optimal incentive coefficient is different under different risk preference combinations.Internalized medical expenses largely avoid the moral hazard of“supporting medicine with drugs”.On this basis,Rabin’s reciprocity preference theory is introduced into the model to study the incentive mechanism design of doctor-patient transaction from the perspective of reciprocity.The results show that when the fixed fee paid by the patient is more than half of the maximum fixed fee that the patient can afford,and the effort of the doctor is more than half of the maximum effort,the doctor and the patient have reciprocal beha-viors,and the benefits of both parties are higher than the benefits of complete rationality.At the same time,the higher the patient’s fixed fee to the doctor,the greater the effort of the doctor.Finally,by comparing the benefits of patients and doctors under the condition of complete rationality and reciprocity preference through numerical simulation,it can be concluded that the benefits of patients and doctors under the condition of reciprocity preference have pareto improvement.