May Arbitral Tribunals Seated in Switzerland and Applying German Law or the CISG Estimate Quantum?

In most arbitrations, the precise amount to be paid by one party to another cannot be ascertained with certainty. Tribunals, therefore, often (have to) resort to estimating quantum issues. The article analyses how arbitrators can - in a dogmatically coherent approach - come to the conclusion that they may indeed do so. The issue is more complex than one may think because under some laws (as e.g. German) the provision on an estimate is included in the civil procedure codes while in others (as e.g. Swiss) it is included in the civil codes. For a tribunal seated in Switzerland, applying German law, that might mean that it cannot apply either provision. The result is obviously wrong. The article gives arbitrators a road map how they can conclude that they may indeed estimate the final amount to be awarded either by (i) qualifying the provision in the codes of civil procedure as substantive in nature or (ii) basing their competence on the general article dealing with the procedure, as e.g. Art. 182, 184 PILA. It also covers the question which is similar although different for tribunals applying the CISG. Finally, arbitrators applying the Swiss Rules in their 2021 version can now directly rely on Article 26(1) Swiss Rules (2021) which allows the tribunal to "determine the [...]burden of proof.". [ABSTRACT FROM AUTHOR]