Resolving Lawsuits with a Decisive Oath: An Economic Analysis

The decisive oath is an interesting but little-known element in some legal proceedings, mostly in civil law traditions. It is different from ordinary (testimonial) oaths that are routinely administered to witnesses at trial with the aim of eliciting only truthful testimony, but which are of dubious value in achieving that end. By contrast, a decisive oath can end a lawsuit in cases where the plaintiff has no evidence. We use a simple economic model of litigation to examine the impact of the decisive oath in resolving lawsuits. To test the implications of the model, we use data from the early nineteenth century Ottoman courts to examine the empirical relationship between the stakes of the case, religious status of defendants, and litigation outcomes. The results show that as the stakes of a case increased: (1) resolution by evidence-based trial or the oath option were both more likely than settlement; (2) the plaintiff was less likely to request an oath from the defendant, with an interaction effect that was also negative and even greater for religious defendants; and (3) the defendant was more likely to take the oath, with an interaction effect that was negative for religious defendants, which offset or reversed the common positive effect. Our analysis contributes both to the theoretical literature on the economics of dispute resolution, and to the historical literature on the role of decisive oaths in resolving legal disputes, especially in Islamic societies and civil law traditions.