Modelling appellate courts' responses in motor injury disputes

Motor third-liability insurance is compulsory in the European Union. We examine the behaviour of Spanish appellate courts in the context of motor liability insurance and pay particular attention to four characterising features. Specifically, we investigate (1) how the appellate court interprets the rules for updating the financial compensation when the courts' ruling is made in a different year to that in which the motor accident occurred; (2) the response of the appellate court when its legal medical evaluation differs from the court's decision; (3) whether the appellate court modifies the criteria when the insurance company was not charged with interest for delaying payment in the first instance; (4) whether the fault allocated by trial courts is revised by the appellate court. We apply a multi-categorical selection mechanism to deal with samples that are potentially non-random. This allows us to separately consider the characteristics of victim's and the insurer's decisions to appeal. The results indicate that disputing agents have significantly different appeal functions, where insurers show a more effective and consistent behaviour than victims.