ARB.6.1 EC – Hormones, para. 27

(WT/DS26/15, WT/DS48/13)

In my view, the party seeking to prove that there are “particular circumstances” justifying a shorter or a longer time has the burden of proof under Article 21.3(c). In this arbitration, therefore, the onus is on the European communities to demonstrate that there are particular circumstances which call for a reasonable period of time of 39 months, and it is likewise up to the United States and Canada to demonstrate that there are particular circumstances which lead to the conclusion that 10 months is reasonable.

ARB.6.2 Canada – Pharmaceutical Patents, para. 47

(WT/DS114/13)

… as immediate compliance is clearly the preferred option under Article 21.3, it is, in my view, for the implementing Member to bear the burden of proof in showing – “[i]f it is impracticable to comply immediately” – that the duration of any proposed period of implementation, including its supposed component steps, constitutes a “reasonable period of time”. And the longer the proposed period of implementation, the greater this burden will be.

ARB.6.3 Canada – Pharmaceutical Patents, para. 55

(WT/DS114/13)

However, certain of the time periods specified by Canada for certain steps toward implementation are not fixed by either law or regulation. Rather, they have been estimated by Canada for purposes of this proceeding. As these estimates are not fixed by either law or regulation, but are only estimates, Canada bears a greater burden of proof in demonstrating their accuracy and legitimacy. And here Canada, in my view, has fallen short.

ARB.6.4 US – 1916 Act, para. 33

(WT/DS136/11, WT/DS162/14)

The parties do not dispute that “immediate” implementation is “impracticable” in this case. I, therefore, consider that the United States bears the burden of proof in showing that the period of 15 months proposed by it is the “shortest period possible” within its legislative system to implement the recommendations and rulings of the DSB in this particular case.