Courts in countries as diverse as Uganda, India, South Africa, and Japan have regularly cited foreign and international law in their decisions, particularly when in the early stages of democratic transition. Other courts, in countries such as Taiwan and Hungary, also rely consistently on comparative sources, but are less likely to identify them explicitly in decisions, in part because of the way in which opinions are drafted. Nevertheless, their adoption of key foreign concepts means that “the impact of foreign constitutional courts is easy to detect in many decisions.”
Part of the explanation for the prevalence of this comparative practice in the democracies formed following World War II is clearly structural—their new constitutions often explicitly incorporated international standards or foreign-rights models into their constitutional commitments. Additionally, many such foreign and comparative references are likely utilitarian; new courts lacking legitimate indigenous jurisprudence may need to borrow early on to speed up the decisionmaking process. Constitutional commitment, however, is only a partial explanation, for in many of these countries the rate of use of foreign and international law references does not seem to track directly with constitutional requirements. In other words, engagement with foreign and international law does not seem to vary measurably between nations based on differences between their specific constitutional commitments. For example, South Africa’s Constitutional Court is among the courts most active in considering the experience of other countries, even though its Constitution does not require it to do so. Similarly, the Ugandan Constitutional Court regularly cites both foreign and international law and practice despite the absence of any explicit constitutional directive. Despite the constitutional directive to consider international law as part of domestic law, the Namibian Supreme and High Courts consider comparative law more frequently than international law in some areas of their jurisprudence.