This article provides a framework for systematically analyzing the practice, function, and consequences of human rights references in investment arbitration. In recent years, investment arbitration witnessed an enormous increase of references to external sources. References to human rights are especially interesting as they defy the alleged inherent conflict of investment and human rights, as well as the presumed fragmentation of international law. By applying both quantitative and qualitative approaches, I analyze how and why human rights references are employed in investor-state arbitration and, ultimately, whether they are able to remedy the legitimacy crisis of investment arbitration.
The empirical analysis is based on 46 awards, which include explicit references to human rights instruments. In the first part, this article examines which human rights instruments are referenced in investment arbitration and how the disputing parties as well as the tribunal engage in human rights referencing. In the second step, the article identifies two strategic functions of referencing human rights: guidance in the determination of substantive provisions and argumentative practice. This article further argues that, from a comparative law perspective, references may help to overcome the indetermination of investment treaties, provide for the balancing of investment and non-investment concerns, and ensure cross-regime consistency. In the third step, this article elaborates on whether those presumed benefits of referencing human rights can be confirmed on the basis of empirical results. It remains to be seen whether the ‘pick and choose’ approach of human rights references is capable of uncovering this legitimating potential.