Liability Under Uncertain Causation – Calculation of Damages in Medical Malpractice Cases

Abstract:     
Assume that epidemiological evidence suggests that patients are cured with 80% when treated correctly but only with 70% if treated negligently. How should one calculate a person’s compensation, who suffered harm after having been negligently treated by a doctor? Under the all-or-nothing principle – commonly attributed to German law – the doctor is either liable for all the harm or nothing. An interesting alternative from a doctrinal and a policy point of view consists in overcoming the all-or-nothing principle and holding the doctor partially liable in all cases where he was found negligent. Liability would be determined proportional to the “lost chance” or the “probability of causation”. There is, however, considerable dispute about the correct calculation method for proportional liability. The main objective of the present analysis is to evaluate proposed calculation methods from a doctrinal and social welfare perspective. The paper argues that proportional liability can be construed as a one-to-one transfer of undisputed doctrinal principles of measuring liability under certainty to situations where causation is uncertain. Moreover, correctly calculated proportional liability also prevents overcompensation of victims and defensive behavior by doctors. Proportional liability is therefore not only desirable from a policy perspective but, as will be argued, can also be implemented on the basis of the current civil code.

Number of Pages in PDF File: 23

Keywords: Proportional Liability, medical malpractice, uncertain causation, Arzthaftung, Proportionalhaftung

JEL Classification: K13

Accepted Paper Series