Can international courts deter? Much scholarship relies on the answer being ‘yes’. In this view, the rulings of international courts are thought to have effects beyond a given case, changing global expectations over the measures ruled on and making further violations less likely. Yet public international law explicitly denies the possibility of such deterrence. Little empirical work assesses these competing claims. In this chapter, we describe the novel approach we have taken in our recent work, by looking to financial markets reactions to World Trade Organization rulings. We ask whether investors downgrade a firm when a policy similar to the one it benefits from has been found in violation in another country. Using a quantitative case study of rulings against Canada’s support of its solar industry, we find measured empirical support for such a deterrent effect. Yet a caveat is in order: the Appellate Body’s rulings appear to exert a greater deterrent effect than ad hoc panellists. The debate over the deterrence effects of courts remains open. Yet our findings suggest that financial markets appear willing to bet on courts deterring similar violations in countries not party to a dispute.

Scandinavia is often hailed as the cradle of peace studies and international law. However, apart from anecdotal evidence we in fact know very little about whether democracies that often portray themselves as the home of human rights actually legitimise these values at home by referring to them in their own case law. By applying original new data, this chapter sets out to develop and discuss a quantitative methodology to measure the impact and legitimacy of international law and courts on the ground among some of the world’s most advanced democracies. We thus provide an innovative analysis mapping how Supreme Courts in Scandinavia over a fifty-year-long time span have cited (or refrained from doing so) international courts’ case law, treaties and conventions. We argue that in conducting such a comprehensive study, we have acquired not only a unique historic picture of the impact of these supranational instruments on domestic legal orders; we also now have a much better idea of whether and to what extent the Supreme Courts in question consider a supranational rule of law legitimate. It is hypothesised, moreover, that majoritarian democracies generally cite significantly fewer international cases and conventions than democracies with a solid national judicial review tradition.

What motivates States to commit to international human rights treaties remains an unanswered question in political science. Many tentative explanations for the observed variation in ratification patterns have been proposed; some are based on intrinsic characteristics of the treaties (the substance of the protected rights and the control mechanism); others are tied to external factors (having originated either from pressure of the international community or in the domestic political system). Yet the empirical evidence supporting the proposed hypotheses remains unsatisfactory. We aim to contribute to this discussion by providing a new systematic examination of the commitment practices in two post-communist countries: the Czech Republic and Slovakia. While both countries have experienced similar international development, propelled by the same international incentives and constraints, their internal political experience differs significantly. This case selection allows us to focus on how domestic political factors and treaty characteristics interact to determine commitment behaviour. Building upon an analysis of government’s manifestos and commitment processes in 192 treaties dealing with human rights, we examine whether Czech and Slovak governments claiming to protect certain human rights are more likely to act accordingly and aim to adopt related international human rights commitments.