Arbitration Ex Aequo et Bono in National Legal Systems - Chapter 4 - International Arbitration Ex Aequo et Bono/Amiable Composition
The legal outline for international arbitration may be defined by the connection of three elements: (i) the national legislations; (ii) the treaties; and (iii) the arbitration rules.
Any and all international arbitrations will be subject to the effects of each one of those elements, to some degree, in general, at the same time and overlapping.
 That is certainly not the only classification possible. There are other forms of classification of “sources” of international arbitration. Fouchard, Gaillard and Goldman (Traité de l’Arbitrage Commercial International, cit., p. 71 et seqq.) suggest the division between sources of public and private origin, according to the nature of the entities that emanate the rules. The sources of public origin are divided into national (essentially the national legislations) and international ones. The latter include: (i) optional instruments, such as arbitration rules proposed by public international institutions, as the UN Commissions and the Model Law); (ii) bilateral agreements, as treaties of legal assistance or other ones that include arbitration as a dispute settlement option (among which those that have a specific arbitration purpose, such as the Algiers Agreements); and (iii) multilateral conventions, such as the New York Convention. The sources of private origin cover: (i) model agreements, as model clauses of institutions and agreements between institutions; (ii) arbitration rules and other rules, such as deontological codes or codes on specific matters, as the administration of evidences; and (iii) arbitration awards. Although this is a more elaborate classification, it focuses in one aspect, the origin of the sources. For the purposes of the study of arbitration ex aequo et bono we deem it more convenient to use a criterion that focuses on the nature of the acts. Some of the items mentioned in the classification of the French authors are encompassed in the three categories adopted in this chapter and others in different chapters of this work (as is the case with the awards). Others, as deontological codes, were not included.
 “2-42 Wherever the parties are from and whatever form and place of arbitration is selected, every arbitration will be situated within and subject to some legal and regulatory systems. In most international arbitrations, there will be an overlap between two or more of these systems, e.g. the law of the place of arbitration and the arbitration rules. The effectiveness of the arbitration and the enforceability of the arbitration award will depend on the relevant law and rules being respected.
2-43 As will be seen throughout this study, in every arbitration there is an underlying national law, normally that of the place of arbitration, which regulate and controls the arbitration. It will be tempered by international arbitration practice and the rules of arbitration, institutional or ad hoc, which the parties may have selected to govern their arbitration. An inevitable question is which shall prevail where the two are in conflict.” Lew, Julian D.M.; Mistelis, Loukas A.; Kröll, Stefan M. Comparative international commercial arbitration. Deventer: Kluwer Law International, 2003. p. 17.