Originally from Arbitrators' Initiative: When, Why and How Should It Be Used? - ASA Special Series No. 45

Arbitrators do take the initiative: they organize the proceedings,
as the case may be, in consultation with the parties; they ask their own
questions, put them to the witnesses, to the experts, and to counsel;
they limit the scope or the duration of the examination of a witness;
they, more rarely, request that a certain witness be heard; they appoint
their own expert, etc.
What gives them the power to do all that? And should there not
be limits to such power?

1. THE FOUNDATION OF THE ARBITRATOR’S POWER TO
TAKE THE INITIATIVE

To this question there can be various answers, depending on
whether the question is to be understood as a technical question, or as
a more, if not philosophical, at least conceptual one.
If we understand it as a technical question, it means: where are
the rules of law that grant arbitrators the power to take the initiative?
Where can they be found in written form?
If we understand the question as one which goes to the very
concept of arbitration, it means: what, in the nature of arbitration,
justifies the power of arbitrators to take the initiative?
1.1. The Question in Its Technical Sense
In order to answer the question in its technical sense, we need to
find express provisions somewhere. And that can only be in the
parties’ agreement, in the law, or in the arbitration rules.
Powers expressly granted by the parties are generally very
limited: the arbitrators’ power of initiative is not a common feature—or
if it is, it is a very limited one—of the arbitration clause, or of terms of
reference. One finds more provisions in the so-called Procedural
Orders n° 1. However, even if the parties have generally expressed
their agreement as to their contents, such provisions are fundamentally
based upon the unilateral power of the arbitrators: on the basis of that