The UNIDROIT Principles as Global Background Law

Uniform Law Review, Vol. 19, no. 4 (2014)

26 Pages Posted: 1 Oct 2014

See all articles by Ralf Michaels

Ralf Michaels

Max Planck Institute for Comparative and International Private Law

Date Written: September 26, 2014


In this contribution I assess, empirically and analytically, what role the UNIDROIT Principles of International Commercial Contracts (PICC) play twenty years after their drafting, and how this role differs from the role for which they were originally intended.

First, I present nine surprising findings concerning the actual use of the PICC. (1) Although most academics discuss whether the PICC can be chosen as applicable law, parties rarely choose the PICC. (2) Adjudicators use the PICC even when they have not been chosen. (3) The PICC are increasingly used as customs or international trade usage although this is not their nature. (4) Although the PICC are catered mainly to arbitration, state court judges apply the PICC at least as often as arbitrators. (5) Although the PICC are transnational, they are used very differently in different countries. (6) Although the PICC are advertised as a comprehensive code, their use as a system is rare, and rarely successful. (7) Most use is made of individual provisions, and, contrary to the claim that the PICC are self-sufficient, in connection wth other laws. (8) Despite their international focus, adjudicators frequently apply the PICC to domestic situations. (9) The PICC are a model more for domestic than international lawmaking.

Secondly, I use these insights towards a concrete goal, namely to determine analytically what role the PICC play in the contemporary legal landscape. I suggest that attempts to characterize the PICC as a non-State code, or even a non-State legal system, for example a new lex mercatoria, are ill-fated — not just theoretically, but also empirically. Instead, I find that their nature is that of a Restatement of global general contract law, and their function is that of a global background law. I also ask what this means for the current state of transnational law.

Thirdly, finally, I suggest some concrete implications for currently relevant questions that emerge from this recognition. These implications concern their use in private international law, their use to interpret the CISG, their relationship with other non-State codifications, and their relationship with a possible global commercial code.

Suggested Citation

Michaels, Ralf, The UNIDROIT Principles as Global Background Law (September 26, 2014). Uniform Law Review, Vol. 19, no. 4 (2014). Available at SSRN:

Ralf Michaels (Contact Author)

Max Planck Institute for Comparative and International Private Law ( email )

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Hamburg, D-20148

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