Christian Waibel

What Drives Fraud in a Credence Goods Market? Evidence from a Field Study

This paper investigates the impact of competition on an expert firms incentive to defraud its customers in a credence goods market. Controlling for the competence of car repair shops, their financial situation, and reputational concerns, we use and complement the data set from a nationwide field study conducted by the German Automobile Association that regularly checks the reliability of garages in Germany. We find that more intense competition lowers a firms incentive to defraud its customers.

Second Opinions in Markets for Expert Services: Experimental Evidence

We experimentally investigate the role of second opinions in markets where experts such as physicians both diagnose and provide the services. Physicians may exploit their informational advantage and overtreat their patients by providing a more costly and expensive treatment than necessary. We show that introducing costly second opinions significantly reduces the level of overtreatment. Lowering search costs leads to significantly more second opinions, but the overtreatment level does not decrease. Under low but not under high search costs, market efficiency rises with the introduction of second opinions, as the reduction in treatment costs due to less overtreatment exceeds the increase in incurred search costs.

Discrimination in Health Care: A Field Experiment on the Impact of Patients' Socio-Economic Status on Access to Care

We employ a large-scale field experiment to investigate the impact of patients’ socioeconomic status on access to care. We request an appointment at more than 1,200 physicians in Austria, varying the educational level of the patient. Our results show that overall patients with a university degree receive an appointment significantly more often than patients without a degree. Differentiating between practice assistants and physicians as responders, we find that physicians provide significantly shorter response times and marginally significant shorter waiting times for appointments for patients with than without a university degree. Our results thus provide unambiguous evidence that discrimination by health providers contributes to the gradient in access to care. Furthermore, we argue that our results are consistent with implicit bias for practice assistants and statistical discrimination based on financial incentives for physicians.

Equity in Health Care: A Field Experiment on the Effect of Socioeconomic Status on Access to Outpatient Care

We employ a large-scale field experiment to investigate the impact of patients’ socio-economic status on access to care. We request an appointment at more than 1,200 physicians in Austria varying the educational level of the patient. Our results show that overall patients with a university degree receive an appointment significantly more often than patients without a degree. Differentiating between practice assistants and physicians as responders to the request, we find that the overall results are driven by practice assistants. Physicians, in contrast, provide significantly shorter response times and earlier appointments for patients with than without university degree. Our results thus provide unambiguous evidence that discrimination by health providers contributes to the gradient in access to care.

Kickbacks, Referrals and Efficiency in Health Care Markets: Experimental Evidence

Abstract How referral fees affect primary care physicians’ behavior is not well understood. We conduct a behavioral experiment on referral fees in which subjects take on the role of physicians. An illustrative theoretical model guides our experimental design and the formulation of behavioral hypotheses for heterogeneously altruistic physician-types. We exogenously vary the level of referral fees paid by specialists to primary care physicians and study the impact of these fees on primary care physicians’ diagnostic effort and referrals. In a separate experimental task, we evaluate primary care physicians’ altruism. In line with our model, introducing medium-sized referral fees significantly increases referrals made by barely altruistic primary care physicians of patients who need specialist treatment, when compared to the baseline without referral fees. High referral fees significantly increase referrals irrespective of physicians’ level of altruism. Surprisingly, diagnostic effort is not significantly affected by referral fees. Implications for economic efficiency are discussed.