PARTY AUTONOMY AND ITS LIMITATIONS IN THE ROME II REGULATION Th.M. de Boer∗1. Choice-of-law principlesParty autonomy is one of the leading principles of contemporary choice of law. Long gone are the days when conflicts scholars still argued that the applicable law could not be displaced by party agreement, as private individuals, by their own volition, cannot rise above the applicable law.1 Not until the 1960’s did it dawn on them that this levitation trick might be supported by the adoption of a conflicts rule allowing the parties to choose the applicable law.2 Since then, party autonomy has gradually gained ground in national and international conflicts legislation, and its scope has been ex-tended from contracts to torts, succession,3 matrimonial property,4 and, in some jurisdictions, even divorce and maintenance.5 Given the acceptance of party autonomy in such a wide range of choice-of-law categories, one is bound to assume that it is supported by a common denominator. It has been argued that the parties’ freedom of choice is justified by the need for legal certainty and predictabil-ity,6 by a ‘subjective theory of the proper law,’7 or ‘for want of a better solution’.8 That does not ex-plain, however, why there are areas of conflicts law in which the parties’ freedom of choice is either limited or non-existent, while there are other areas in which the need for predictable solutions is met∗Professor of private international law and comparative law at the University of Amsterdam. The text of this article was concluded in December 2007.1. In this vein, e.g.: J.P.Niboyet, La théorie de l’autonomie de la volonté, Recueil des Cours 1927 (I), p. 53 ff.; M. Caleb,Essai sur le principe de l’autonomie de la volonté en droit international privé, Sirey, Paris, 1927, p. 167 ff.; I Henri Hijmans, Algemeene Problemen van Internationaal Privaatrecht, Tjeenk Willink, Zwolle, 1937, p. 169 ff.; P. Scholten,C. Asser’s Handleiding tot de beoefening van het Nederlandsch Burgerlijk Recht, Algemeen Deel, Tjeenk Willink,Zwolle, 1954, p. 211.2. Frank Vischer, Internationales Vertragsrecht, Die kollisonsrechtlichen Reglen der Anknüpfung bei internationalenVerträgen, Verlag Stämpfli |& Cie, Bern, 1962, p. 23, citing W. Niederer, Einführung in die allgemeinen Lehren des in-ternationalen Privatrechts, 1954, p. 193, and a decision by the Swiss Bundesgericht, BGE 79 II 299.3. Cf. Article 5 Hague Convention of 1 August 1989 on the Law Applicable to Succession to the Estates of DeceasedPersons; Articles 90(2) and 91(2) Swiss Bundesgesetz über das Internationale Privatrecht (IPRG); Article 79 Belgian Wetboek van Internationaal Privaatrecht.4. Cf. Articles 3 and 6 Hague Convention of 14 March 1978 on the Law Applicable to Matrimonial Property Regimes;Article 52 Swiss IPRG; Article 15 German Einführungsgesetz zum Bürgerlichen Gesetzbuche(EGBGB); Article 49 Belgian Wetboek van Internationaal Privaatrecht.5. A limited freedom of choice already exists in several EC member states and is also endorsed in the various drafts of theso-called ‘Rome III Regulation’ (more properly: the ‘Brussels II-ter Regulation’) and in the drafts of a Regulation on in-ternational maintenance obligations.6. This used to be a popular proposition in the 1960’s and 1970’s. Surprisingly, it is still the main argument supportingparty autonomy in the Rome II Regulation; infra § 2.7. F.A. Mann, The Proper Law of a Contract, 3 ICLQ p. 60 ff. (1950): ‘subjective theory of the proper law: that legalsystem which, by their express or implied intention, the parties intended to apply’. Contra: J.H.C. Morris, The Proper Law of a Contract: A Reply, 3 ICLQ, p. 197 ff., at p. 207 (1950): ‘the subjective theory of the proper law is no more than a fiction ...’.8. In a rather pedantic article – my first attempt at academic writing – I took the view that, in a choice-of-law methodwhich is geared to the designation of the law most closely connected, party autonomy is an anomaly to be tolerated only – for want of a better solution – if objective choice-of-law rules prove to be inconclusive: Th.M. de Boer, Subjectieve verwijzing: anomalie of grondbeginsel?, in: H.U. Jessurun d’Oliveira e.a., Partij-invloed in het internationaal privaat-recht, Kluwer, Deventer, 1974, p. 47-72, at p. 68. My contribution to this collection of essays is best forgotten.1