WTO Dispute Settlement Mechanism(6)

chapter vi
general rules of evidence
under the wto jurisprudence


outline

i burden of proof under the wto jurisprudence
(ⅰ) general rules well established in violation complaints
(ⅱ) burden of proof in case of invoking an exception
(ⅲ) special rules concerning non-violation claims
(ⅳ) summary and conclusions
ii admissibility of certain evidences
(ⅰ) evidence obtained from prior consultations
(a) procedural concern: confidentiality of consultations
(b) substantial concern: necessity or relevance of evidence
(ⅱ) arguments before domestic investigative authorities
(ⅲ) arguments submitted after the first substantive meeting
(a) there is a significant difference between the claims and the arguments supporting those claims.
(b)there is no provision establishing precise deadlines for the presentation of evidence.
iii panel’s right to seek information
(ⅰ) a grant of discretionary authority
(ⅱ) the admissibility of non-requested information
(ⅲ) summary and conclusions
iv adverse inferences from party’s refusal to provide information requested
(ⅰ) the authority of a panel to request information from a party to the dispute
(ⅱ) the duty of a member to comply with the request of a panel to provide information
(ⅲ) the drawing of adverse inferences from the refusal of a party to provide information requested by the panel
v concluding remarks

i burden of proof under the wto jurisprudence
generally, the question of whether a member acted in accordance with the agreement hinges frequently on whether and to what extent that member must demonstrate compliance or the complaint must demonstrate a lack of compliance. it is demonstrated that the burden of proof is a procedural concept which speaks to the fair and orderly management and disposition of a dispute. this is the issue of “the ultimate burden of proof for establishing a claim or a defence”. in this respect, the panel report on us-copyright act (ds160) states, “[w]hile a duty rests on all parties to produce evidence and to cooperate in presenting evidence to the panel, this is an issue that has to be distinguished from the question of who bears the ultimate burden of proof for establishing a claim or a defence”.1
(i) general rules well established in violation complaints
art. 3.8 of the dsu provides that in cases where there is an infringement of the obligations assumed under a covered agreement -- that is, in cases where a violation is established -- there is a presumption of nullification or impairment. however, the issue of burden of proof here is not what happens after a violation is established; the issue is which party must first show that there is, or is not, a violation. in this respect, a number of gatt 1947 panel reports contain language supporting the proposition that the burden of establishing a violation under article xxiii:1(a) of the gatt 1947 was on the complaining party, i.e., it was for

the complaining party to present a prima facie case of violation before a panel. this rule is taken on by the dsb.
with regard to the issue of burden of proof, the appellate body in us-shirts and blouses (ds33) rules that: “in addressing this issue, we find it difficult, indeed, to see how any system of judicial settlement could work if it incorporated the proposition that the mere assertion of a claim might amount to proof. it is, thus, hardly surprising that various international tribunals, including the international court of justice, have generally and consistently accepted and applied the rule that the party who asserts a fact, whether the claimant or the respondent, is responsible for providing proof thereof. also, it is a generally-accepted canon of evidence in civil law, common law and, in fact, most jurisdictions, that the burden of proof rests upon the party, whether complaining or defending, who asserts the affirmative of a particular claim or defence. if that party adduces evidence sufficient to raise a presumption that what is claimed is true, the burden then shifts to the other party, who will fail unless it adduces sufficient evidence to rebut the presumption.” 2and this ruling is demonstrated to be well established in subsequent cases as a general rule concerning burden of proof.
for example, in argentina-leather (ds155), the panel states: “the relevant rules concerning burden of proof, while not expressly provided for in the dsu, are well established in wto jurisprudence. the general rule is set out in the appellate body report on united states - measure affecting imports of woven wool shirts and blouses, wherein it is stated that: ‘it is a generally-accepted canon of evidence in civil law, common law and, in fact, most jurisdictions, that the burden of proof rests upon the party, whether complaining or defending, who asserts the affirmative of a particular claim or defence. if that party adduces evidence sufficient to raise a presumption that what is claimed is true, the burden then shifts to the other party, who will fail unless it adduces sufficient evidence to rebut the presumption’.” 3
and in us-cotton yarn (ds192), the panel rules in pertinent part: “the appellate body and subsequent panels endorsed this principle that a complainant bears the burden of proof. for example, the appellate body, in ec - hormones, states as follows: ‘… the initial burden lies on the complaining party, which must establish a prima facie case of inconsistency with a particular provision of the sps agreement on the part of the defending party, or more precisely, of its sps measure or measures complained about. when that prima facie case is made, the burden of proof moves to the defending party, which must in turn counter or refute the claimed inconsistency. this seems straightforward enough and is in conformity with our ruling in united states - shirts and blouses, which the panel invokes and which embodies a rule applicable in any adver

sarial proceedings.’” 4
as a whole, on the one hand, as ruled by the panel in argentina-ceramic floor tiles (ds189), “[w]e recall that the burden of proof in wto dispute settlement proceedings rests with the party that asserts the affirmative of a particular claim or defence. it implies that the complaining party will be required to make a prima facie case of violation of the relevant provisions of the wto agreement, which is for the defendant…to refute. in this regard, the appellate body has stated that ‘... a prima facie case is one which, in the absence of effective refutation by the defending party, requires a panel, as a matter of law, to rule in favour of the complaining party presenting the prima facie case’…”; 5 on the other hand, as noted in the panel report on us-copyright act (ds160), “[t]he same rules apply where the existence of a specific fact is alleged. we note that a party who asserts a fact, whether the claimant or the respondent, is responsible for providing proof thereof. it is for the party alleging the fact to prove its existence. it is then for the other party to submit evidence to the contrary if it challenges the existence of that fact”. 6
in sum, with respect to the general rules of burden of proof in the context of violation complaints, as ruled by the panel in japan-film (ds44): “[w]e note that as in all cases under the wto/gatt dispute settlement system - and, indeed, as the appellate body recently stated, under most systems of jurisprudence - it is for the party asserting a fact, claim or defence to bear the burden of providing proof thereof. once that party has put forward sufficient evidence to raise a presumption that what is claimed is true, the burden of producing evidence then shifts to the other party to rebut the presumption.…”. 7certainly, as noted by the appellate body in us-shirts and blouses (ds33), “[i]n the context of the gatt 1994 and the wto agreement precisely how much and precisely what kind of evidence will be required to establish such a presumption will necessarily vary from measure to measure, provision to provision and case to case”.8
(ii) burden of proof in case of invoking an exception
as discussed above, generally, the burden of proof rests upon the party, whether complaining or defending, who asserts a fact or the affirmative of a particular claim or defence. as to be shown, this rule applies equally even in case of invoking an exception.
in this context, it is a general principle of law, well-established by panels in prior gatt/wto practice, that the party (the defendant) which invokes an exception in order to justify its action carries the burden of proof that it has fulfilled the conditions for invoking the exception. however, in the author’s view, to understand the issue concerning burden of proof in case of invoking an exception, which is different from the relatively clear burden of establishing a prima facie case of violation on the complaining party, it’s helpful to

stress some points here, among which the key point is to be cautious while determine which defence is “affirmative” and therefore burdens the defendant to provide sufficient evidence to rebut the challenged violation.
in united states-shirts and blouses (ds33), india argues that it was “customary gatt practice” that the party invoking a provision which had been identified as an exception must offer proof that the conditions set out in that provision were met. the appellate body acknowledges that several gatt 1947 and wto panels have required such proof of a party invoking a defence, such as those found in art. xx or art. xi:2(c)(i), to a claim of violation of a gatt obligation, such as those found in arts. i:1, ii:1, iii or xi:1. arts. xx and xi:(2)(c)(i) are limited exceptions from obligations under certain other provisions of the gatt 1994, not positive rules establishing obligations in themselves. they are in the nature of affirmative defences. it is only reasonable that the burden of establishing such a defence, i.e. invoking an exception in the nature of affirmative defences, should rest on the party asserting it. 9
however, as ruled by the appellate body in ec-hormones (ds26/ds48), “[t]he general rule in a dispute settlement proceeding requiring a complaining party to establish a prima facie case of inconsistency with a provision of …[the covered agreements] before the burden of showing consistency with that provision is taken on by the defending party, is not avoided by simply describing that same provision as an ‘exception’. in much the same way, merely characterizing a treaty provision as an ‘exception’ does not by itself justify a ‘stricter’ or ‘narrower’ interpretation of that provision than would be warranted by examination of the ordinary meaning of the actual treaty words, viewed in context and in the light of the treaty's object and purpose, or, in other words, by applying the normal rules of treaty interpretation. it is also well to remember that a prima facie case is one which, in the absence of effective refutation by the defending party, requires a panel, as a matter of law, to rule in favour of the complaining party presenting the prima facie case.” 10
in short, during the process of the establishment of a violation, it’s generally up to the complainant to provide evidence concerning inconsistency, and only in case of limited exceptions the burden of proof rests upon the defending party invoking a defence in the nature of affirmative defences, such as those found in art. xx or art. xi:2(c)(i) of the gatt 1994.
(iii) special rules concerning non-violation claims
as suggested by the corresponding provisions, the most significant difference between violation complaints under art. xxiii:1(a) of the gatt 1994 and non-violation ones under art. xxiii:1(b) is, while, when violation complaints are brought under art. xxiii:1(a), the infringement of an obligation of the agreements is considered prima facie to constitute a

case of nullification or impairment, from the fact of violation alone, by establishing a formal presumption, such a presumption does not exist in non-violation cases.
with the lack of such a presumption, and given the nature of the factually complex disputes and particular claims of non-violation nullification or impairment, the resolution of issues relating to the proper allocation of the burden of proof is of particular importance. in case of non-violation nullification or impairment, i.e., where the application of art. xxiii:1(b) is concerned, art. 26.1(a) of the dsu and panel practice in the context of the wto agreement and gatt jurisprudence confirm that this is an exceptional course of action for which the complaining party bears the burden of providing a detailed justification to back up its allegations.
this requirement has been recognized and applied by a number of gatt panels. for example, the panel on uruguayan recourse to art. xxiii noted that in cases “where there is no infringement of gatt provisions, it would be ... incumbent on the country invoking article xxiii to demonstrate the grounds and reasons for its invocation. detailed submissions on the part of that contracting party on these points were therefore essential for a judgement to be made under this article”. and the panel on us - agricultural waiver noted, in applying the 1979 codification of this rule: “the party bringing a complaint under [article xxiii:1(b)] would normally be expected to explain in detail that benefits accruing to it under a tariff concession have been nullified or impaired”.
art. 26.1(a) of the dsu codifies the prior gatt practice, which provides in relevant part: “the complaining party shall present a detailed justification in support of any complaint relating to a measure which does not conflict with the relevant covered agreement ...”.
and in japan – film (ds44), the panel confirms the rule on burden of proof in the context of non-violation complaints under art. xxiii:1(b): “consistent with the explicit terms of the dsu and established wto/gatt jurisprudence, and recalling the appellate body ruling that ‘precisely how much and precisely what kind of evidence will be required to establish ... a presumption will necessarily vary from ... provision to provision’, we thus consider that the united states [the complaining party], with respect to its claim of non-violation nullification or impairment under article xxiii:1(b), bears the burden of providing a detailed justification for its claim in order to establish a presumption that what is claimed is true. it will be for japan [the defendant] to rebut any such presumption.” 11
(iv) summary and conclusions
to sum up, in the context of violation complaints under art. xxiii:1(a) of the gatt 1994, as ruled by the panel in turkey-textile and clothing products (ds34): “the rules on burden of proof are now well established in the wto and can be summed up as follows: (a) it is for the complain

ing party to establish the violation it alleges; (b) it is for the party invoking an exception or an affirmative defense to prove that the conditions contained therein are met; and (c) it is for the party asserting a fact to prove it.” 12
and in the context of non-violation complaints under art. xxiii:1(b) of the gatt 1994, “[the complainant], with respect to its claim of non-violation nullification or impairment under article xxiii:1(b), bears the burden of providing a detailed justification for its claim in order to establish a presumption that what is claimed is true. it will be for [the defendant] to rebut any such presumption”.

ii admissibility of certain evidences
generally, as a matter of process before the panel, the complainant will submit its arguments and evidence and the respondent will respond to rebut the complainant’s claims. however, as noted above, the allocation of burden of proof is only applicable to determine precisely how much and precisely what kind of evidence will be required to establish a presumption that what is claimed is true. next, once the party asserting a fact or the affirmative of a particular claim or defence has succeeded in raising a presumption that its claim is true, it is incumbent on panels, before whom such a presumption is successfully raised, to assess the merits of all the arguments made and the admissibility, relevance and weight of all the factual evidence submitted with a view to establishing whether the party contesting the presumption raised has successfully rebutted it. and at the end of this process, it is for the panel to weigh and assess the evidence submitted and arguments asserted by both parties in order to reach conclusions as to whether the claims raised by the complainant are ultimately well-founded or successfully rebutted.
however, the following paragraphs will not deal with everything involved in the process of panels’ assessment of arguments or evidence, which arises logically after the allocation of burden of proof, but focus on the admissibility issue, i.e., a matter of to what extent and how the evidence available to panels should be based on to determine whether, on balance, alleged impairment or nullification exists. in this respect, as to be demonstrated in the following paragraphs, panels enjoy their broad discretion in admitting various evidences.
(i) evidence obtained from prior consultations
according to the wto jurisprudence, the dsb is not involved in consultations process although they are a crucial and integral part of the dsu. nothing in the text of the dsu or other covered agreements provides that the scope of a panel's work is governed by the scope of prior consultations.13 however, as to be noted below, panels won’t preclude those evidences merely because they are obtained during the course of consultations. indeed, information obtained during the course of consultations may enable the complainant to focus the scope of the matter with respe

ct to which it seeks establishment of a panel, thus, to some extent will assist panel’s examination of measures at issue to make objective assessment with the access of such information offered to the panel.
（a）procedural concern: confidentiality of consultations
in australia-automotive leather (ds126), australia appears to be asking the panel to rule that, the united states is limited to relying on the facts and arguments explicitly set out in its request for consultations in presenting its case to the panel. as to this objection, the panel rules as follows: 14
“as australia rightly notes, article 4.6 of the dsu provides that ‘[c]onsultations shall be confidential, and without prejudice to the rights of any member in any further proceedings’. however, in our view, this does not mean that facts and information developed in the course of consultations held pursuant to one request cannot be used in a panel proceeding concerning, as it does in this case, the same dispute, between the same parties, conducted pursuant to another, different request.
we recall that article 11 of the dsu obliges a panel to conduct ‘an objective assessment of the matter before it’. as discussed earlier, any evidentiary rulings we make must be consistent with this obligation. the panel in korea - taxes on alcoholic beverages recently confirmed the right of a party to a wto dispute to use information learned in consultations in panel proceedings. after noting the requirement of confidentiality in article 4.6 of the dsu, which the panel viewed as ‘essential if the parties are to be free to engage in meaningful consultations’, the panel continued: ‘however, it is our view that this confidentiality extends only as far as requiring the parties to the consultations not to disclose any information obtained in the consultations to any parties that were not involved in those consultations. we are mindful of the fact that the panel proceedings between the parties remain confidential, and parties do not thereby breach any confidentiality by disclosing in those proceedings information acquired during the consultations. indeed, in our view, the very essence of consultations is to enable the parties [to] gather correct and relevant information, for purposes of assisting them in arriving at a mutually agreed solution, or failing which, to assist them in presenting accurate information to the panel. it would seriously hamper the dispute settlement process if the information acquired during consultations could not be subsequently used by any party in the ensuing proceedings’15.”
furthermore, so far as the confidentiality of consultations is concerned, the admissibility of information obtained from consultations doesn’t alter as a result of third party participation in the panel proceedings. as ruled by the panel in mexico-hfcs (ds132): “it would seriously hamper the dispute settlement process if a party could not use information obtained in the consultations in subsequent p

anel proceedings merely because a third party which did not participate in the consultations chooses to participate in the panel proceedings. as … third party participation in the panel proceedings cannot be vetoed by the parties to the proceeding. in our view, it would be anomalous if the decision of a member to participate in a panel proceeding as a third party when it did not, or could not, participate as a third party in the underlying consultations had the effect of limiting the evidence that could be relied upon in the panel proceeding by precluding the introduction of information obtained during the consultations. third parties are subject to the same requirement to maintain the confidentiality of panel proceedings as are parties. we therefore conclude that the requirement to maintain the confidentiality of consultations is not violated by the inclusion of information obtained during consultations in the written submission of a party provided to a third party in the subsequent panel proceeding even if that third party did not participate in the consultations.” 16
(b) substantial concern: necessity or relevance of evidence
in ec-bed linen (ds141), the panel notes that it seems that the evidence concerning the consultations is at best unnecessary, and may be irrelevant. however, the panel rules that, that said, “merely because the evidence is unnecessary or irrelevant does not require us to exclude it”. and they come to this ruling by stating: 17
“a panel is obligated by article 11 of the dsu to conduct ‘an objective assessment of the matter before it’. the panel in australia-automotive leather observed that:
‘any evidentiary rulings we make must, therefore, be consistent with this obligation. in our view, a decision to limit the facts and arguments that the united states may present during the course of this proceeding to those set forth in the request for consultations would make it difficult, if not impossible, for us to fulfill our obligation to conduct an "objective assessment" of the matter before us.’
similarly in this case, we consider that it is not necessary to limit the facts and arguments india may present, even if we might consider those facts or arguments to be irrelevant or not probative on the issues before us. in our view, there is a significant and substantive difference between questions concerning the admissibility of evidence, and the weight to be accorded evidence in making our decisions. that is, we may choose to allow parties to present evidence, but subsequently not consider that evidence, because it is not relevant or necessary to our determinations or is not probative on the issues before it. in our view, there is little to be gained by expending our time and effort in ruling on points of ‘admissibility’ of evidence vel non. ”
in addition, under art. 13.2 of the dsu, panels have a general right to seek information “from any relevant source”. “in this context, we consider that, as a general rule, p

anels have wide latitude in admitting evidence in wto dispute settlement. the dsu contains no rule that might restrict the forms of evidence that panels may consider. moreover, international tribunals are generally free to admit and evaluate evidence of every kind, and to ascribe to it the weight that they see fit. ”18
as one legal scholar has noted: “the inherent flexibility of the international procedure, and its tendency to be free from technical rules of evidence applied in municipal law, provide the ‘evidence’ with a wider scope in international proceedings . . . generally speaking, international tribunals have not committed themselves to the restrictive rules of evidence in municipal law. they have found it justified to receive every kind and form of evidence, and have attached to them the probative value they deserve under the circumstances of a given case.”19
in sum, “[i]t has clearly been held in the wto that information obtained in consultations may be presented in subsequent panel proceedings”.20 “this is unlike the situation before many international tribunals, which often refuse to admit evidence obtained during settlement negotiations between the parties to a dispute. the circumstances of such settlement negotiations are clearly different from wto dispute settlement consultations, which are, as the appellate body has noted, part of the means by which facts are clarified before a panel proceeding.”21in all events, as ruled by the panel in us-line pipe (ds202), “[o]ur decision not to exclude the information does not prejudge in any way the issue of whether the panel will use the information, nor whether the information is relevant to the matter at hand.” 22 there is a significant and substantive difference between questions concerning the admissibility of evidence, and the weight to be accorded evidence in making decisions.
(ii) arguments before domestic investigative authorities
with respect to panels’ examination of factual determinations by domestic investigative authorities in fields concerning countervailing measures, anti-dumping duties and safeguards etc., the appellate body has ruled that, “[s]o far as fact-finding by panels is concerned, their activities are always constrained by the mandate of article 11 of the dsu: the applicable standard is neither de novo review as such, nor ‘total deference’, but rather the ‘objective assessment of the facts’. many panels have in the past refused to undertake de novo review, wisely, since under current practice and systems, they are in any case poorly suited to engage in such a review. on the other hand, ‘total deference to the findings of the national authorities’, it has been well said, ‘could not ensure an“objective assessment”as foreseen by article 11 of the dsu’”.23 and the “nor ‘total deference’” standard suggests that panels will not simply accept the conclusions of the competent authorities. then the following paragraphs will get down to the issue of the admissibility

of arguments or evidence raised before domestic investigative authorities. in this respect, the appellate body rules in us-lamb meat (ds177/ds178) that: 24
“in our report in thailand - anti-dumping duties on angles, shapes and sections of iron or non-alloy steel h-beams from poland, in the course of our examination of the specificity of poland's request for the establishment of a panel under article 6.2 of the dsu, we said: ‘the panel's reasoning seems to assume that there is always continuity between claims raised in an underlying anti-dumping investigation and claims raised by a complaining party in a related dispute brought before the wto. this is not necessarily the case. the parties involved in an underlying anti-dumping investigation are generally exporters, importers and other commercial entities, while those involved in wto dispute settlement are the members of the wto. therefore, it cannot be assumed that the range of issues raised in an anti-dumping investigation will be the same as the claims that a member chooses to bring before the wto in a dispute.’
although the claim under examination in that appeal was different, the same reasoning applies in respect of the relationship between domestic investigations culminating in the imposition of a safeguard measure, and dispute settlement proceedings under the dsu regarding that safeguard measure. in arguing claims in dispute settlement, a wto member is not confined merely to rehearsing arguments that were made to the competent authorities by the interested parties during the domestic investigation, even if the wto member was itself an interested party in that investigation. likewise, panels are not obliged to determine, and confirm themselves the nature and character of the arguments made by the interested parties to the competent authorities. arguments before national competent authorities may be influenced by, and focused on, the requirements of the national laws, regulations and procedures. on the other hand, dispute settlement proceedings brought under the dsu concerning safeguard measures imposed under the agreement on safeguards may involve arguments that were not submitted to the competent authorities by the interested parties.
furthermore, we recall that, in united states - wheat gluten safeguard, we reversed a finding by the panel that competent authorities are obliged to evaluate only those other relevant factors, under article 4.2(a), which were actually raised by the interested parties during the investigation before it. we said there that competent authorities have an independent duty of investigation and that they cannot "remain passive in the face of possible short-comings in the evidence submitted, and views expressed, by the interested parties." in short, competent authorities are obliged, in some circumstances, to go beyond the arguments that were advanced by the interested parties during the investigation. as competent authorities themselves are obliged, in some

circumstances, to go beyond the arguments of the interested parties in reaching their own determinations, so too, we believe, panels are not limited to the arguments submitted by the interested parties to the competent authorities in reviewing those determinations in wto dispute settlement.
we wish to emphasize that the discretion that wto members enjoy to argue dispute settlement claims in the manner they deem appropriate does not, of course, detract from their obligation, under article 3.10 of the dsu, ‘to engage in dispute settlement procedures 'in good faith in an effort to resolve the dispute’. it follows that wto members cannot improperly withhold arguments from competent authorities with a view to raising those arguments later before a panel. in any event, as a practical matter, we think it unlikely that a member would do so.”
(iii) arguments submitted after the first substantive meeting
the appellate body have observed that: “it is also true, however, that the working procedures in appendix 3 do contemplate two distinguishable stages in a proceeding before a panel. paragraphs 4 and 5 of the working procedures address the first stage …the second stage of a panel proceeding is dealt with in paragraph 7…under the working procedures in appendix 3, the complaining party should set out its case in chief, including a full presentation of the facts on the basis of submission of supporting evidence, during the first stage. the second stage is generally designed to permit ‘rebuttals’ by each party of the arguments and evidence submitted by the other parties.”25
in addition, the appellate body rules that, “[a panel request] often forms the basis for the terms of reference of the panel pursuant to article 7 of the dsu”26. and the panel request is normally submitted before the first substantive meeting. subsequently, the defendant party has occasionally contested that panels should reject submissions of new evidence or arguments made after the first substantive meeting. in this respect, the author thinks it necessary to clarify several points as follows:
(a) there is a significant difference between the claims and the arguments supporting those claims.
as ruled by the appellate body in ec-bananas (ds27), art. 6.2 of the dsu requires that “the claims, but not the arguments”, must all be specified sufficiently in the request for the establishment of a panel. with this regard, the appellate body rule that, “… [i]n our view, there is a significant difference between the claims identified in the request for the establishment of a panel, which establish the panel's terms of reference under article 7 of the dsu, and the arguments supporting those claims, which are set out and progressively clarified in the first written submissions, the rebuttal submissions and the first and second panel meetings with the parties”.27
and as clarified by the panel in thailand-iron and h-beams (ds122), “…article 6.2 dsu does not relate directly to the suff

iciency of the subsequent written and oral submissions of the parties in the course of the proceedings, which may develop the arguments in support of the claims set out in the panel request.…”.28 also, the arbitrators in the ec-hormones (ds26) case observe that, “… [p]anels are inhibited from addressing legal claims falling outside their terms of reference. however, nothing in the dsu limits the faculty of a panel freely to use arguments submitted by any of the parties -- or to develop its own legal reasoning -- to support its own findings and conclusions on the matter under its consideration”.29
(b)there is no provision establishing precise deadlines for the presentation of evidence.
in this respect, for example, the appellate body in australia-salmon (ds18) rules that: “more generally, …we note that the working procedures in appendix 3 of the dsu do not establish precise deadlines for the submission of evidence. under the provisions of article 12.1 of the dsu, panels are permitted to establish their own working procedures, in addition to those set out in appendix 3. …we note that article 12.2 of the dsu provides that ‘[p]anel procedures should provide sufficient flexibility so as to ensure high-quality panel reports, while not unduly delaying the panel process.’ however, a panel must also be careful to observe due process, which entails providing the parties adequate opportunity to respond to the evidence submitted. whether the panel afforded australia adequate opportunity to respond is the question addressed in the next section.”30
also, the appellate body in argentina-footwear (ds56) rules that, “article 11 of the dsu does not establish time limits for the submission of evidence to a panel. article 12.1 of the dsu directs a panel to follow the working procedures set out in appendix 3 of the dsu, but at the same time authorizes a panel to do otherwise after consulting the parties to the dispute. the working procedures in appendix 3 also do not establish precise deadlines for the presentation of evidence by a party to the is true that the working procedures ‘do not prohibit’ submission of additional evidence after the first substantive meeting of a panel with the parties…”.31
the panel in canada-civilian aircraft (ds70) refers to this ruling and states in detail as:32
“we recall that the appellate body found in argentine footwear that neither article 11 of the dsu, nor the working procedures in appendix 3 of the dsu, establish precise deadlines for the presentation of evidence by parties to a dispute. …
in our opinion, an absolute rule excluding the submission of evidence by a complaining party after the first substantive meeting would be inappropriate, since there may be circumstances in which a complaining party is required to adduce new evidence in order to address rebuttal arguments made by the respondent. furthermore, there may be instances, as in the present case, where a party is required to submit new eviden

ce at the request of the panel. for these reasons, we rejected canada's request for a preliminary ruling that the panel should not accept new evidence submitted by brazil after the first substantive meeting.
we also consider that we are not bound to exclude the submission of new allegations after the first substantive meeting. we can see nothing in the dsu, or in the appendix 3 working procedures, that would require the submission of new allegations to be treated any differently than the submission of new evidence. indeed, one could envisage situations in which the respondent might present information to a panel during the first substantive meeting that could reasonably be used as a basis for a new allegation by the complaining party. provided the new allegation falls within the panel's terms of reference, and provided the respondent party's due process rights of defence are respected, we can see no reason why any such new allegation should necessarily be rejected by the panel as a matter of course, simply because it is submitted after the first substantive meeting with the parties. we consider that this approach is consistent with the appellate body's ruling in european communities - bananas that ‘there is no requirement in the dsu or in gatt practice for arguments on all claims relating to the matter referred to the dsb to be set out in a complaining party's first written submission to the panel. it is the panel's terms of reference, governed by article 7 of the dsu, which set out the claims of the complaining parties relating to the matter referred to the dsb’.
[…]
as noted above, there is nothing in the dsu, or in the appendix 3 working procedures, to prevent a party submitting new evidence or allegations after the first substantive meeting. we can see no basis in the dsu to treat the submission of affirmative defences after the first substantive meeting any differently. thus, although it is desirable that affirmative defences, as with any claim, should be submitted as early as possible, there is no requirement that affirmative defences should be submitted before the end of the first substantive meeting with the parties. provided that due process is respected, we see nothing to prohibit the submission of affirmative defences after the first substantive meeting with the parties.”
in sum, as provided for in art. 12.2 of the dsu, “[p]anel procedures should provide sufficient flexibility so as to ensure high-quality panel reports, while not unduly delaying the panel process.” the working procedures in appendix 3 of the dsu do not establish precise deadlines for the submission of evidence; there is nothing in the dsu, or in the appendix 3 working procedures, to prevent a party providing new submissions after the first substantive meeting. and as noted above, “the working procedures in their present form do not constrain panels with hard and fast rules on deadlines for submitting evidence.”33
however, a panel must also be careful to

observe due process, which entails providing the parties adequate opportunity to respond to the evidence submitted. just as noted by a panel in this respect, “[u]ntil the wto members agree on different and more specific rules on this regard, our main concern is to ensure that ‘due process’ is respected and that all parties to a dispute are given all the opportunities to defend their position to the fullest extent possible.” 34

iii panel’s right to seek information
a panel is obligated by art. 11 of the dsu to conduct “an objective assessment of the matter before it”, any evidentiary rulings made by panels must be consistent with this obligation. therefore, to fulfil their functions as provided in art. 11 of the dsu to “make an objective”, panels are not limited to the arguments submitted by the participants in wto dispute settlement. panels cannot remain passive in the face of possible shortcomings in the evidence submitted, and views expressed, by the interested parties. and they are obliged, in some circumstances, to go beyond the arguments that were advanced by the parties during the process in reaching their own conclusions.
in fact, the dsu gives panels different means or instruments for complying with art. 11; among these is the right to “seek information and technical advice” as expressly spelled out in art. 13 of the dsu. art. 13.1 of the dsu states that a panel has “the right to seek information and technical advice from any individual or body which it deems appropriate”. art. 13.2 further provides that panels may “seek information from any relevant source and may consult experts to obtain their opinion on certain aspects of the matter”.35
(i) a grant of discretionary authority
pursuant to art. 13 of the dsu, panels have a significant investigative authority; a panel is entitled to seek information and advice from any relevant source it chooses. as to be demonstrated in the following paragraphs, the right to seek information vested in panels by art. 13 of the dsu is “a grant of discretionary authority”.
for example, the appellate body rules in japan-agriculture products (ds76) that: “…article 13.1 of the dsu gives a panel ‘... the right to seek information and technical advice from any individual or body which it deems appropriate’. pursuant to article 13.2 of the dsu, a panel may seek information from any relevant source and may consult experts to obtain their opinions on certain aspects of the matter at issue. this is a grant of discretionary authority: a panel is not duty-bound to seek information in each and every case or to consult particular experts under this provision. we recall our statement in ec measures concerning meat and meat products (hormones) that article 13 of the dsu enables a panel to seek information and technical advice as it deems appropriate in a particular case, and that the dsu leaves ‘to the sound discretion of a panel the determination of whether the establishment of an expert review g

roup is necessary or appropriate’. just as a panel has the discretion to determine how to seek expert advice, so also does a panel have the discretion to determine whether to seek information or expert advice at all.”36
in addition, the exercise of the “discretionary authority” enjoyed by panels to seek information is not conditional as a preliminary matter on the establishment of a prima facie case. in canada-civilian aircraft (ds70), the panel rules that, “a panel's right to seek information is governed by article 13.1 of the dsu. there is nothing in article 13.1 to suggest that a panel's right to seek information is restricted to matters in respect of which the complaining party has been deemed (as a preliminary matter) to have established a prima facie case. the only express restriction on a panel's right to seek information is the article 13.1 obligation for a panel to ‘inform the authorities’ of a member before seeking information or advice from any individual or body within the jurisdiction of that member. in our opinion, any requirement that panels should provide preliminary rulings on whether the complaining party has established a prima facie case before seeking information or advice under article 13.1 could render that provision ineffective. this is because in certain circumstances a panel may consider it appropriate to seek information or advice precisely in order to determine whether the complaining party has established a prima facie case….”. 37 and the appellate body confirms this ruling.
the appellate body in canada-civilian aircraft (ds70) rules that: “a prima facie case, it is well to remember, is a case which, in the absence of effective refutation by the defending party (that is, in the present appeal, the member requested to provide the information), requires a panel, as a matter of law, to rule in favour of the complaining party presenting the prima facie case. there is, as noted earlier, nothing in either the dsu or the scm agreement to support canada's assumption. to the contrary, a panel is vested with ample and extensive discretionary authority to determine when it needs information to resolve a dispute and what information it needs. a panel may need such information before or after a complaining or a responding member has established its complaint or defence on a prima facie basis. a panel may, in fact, need the information sought in order to evaluate evidence already before it in the course of determining whether the claiming or the responding member, as the case may be, has established a prima facie case or defence. furthermore, a refusal to provide information requested on the basis that a prima facie case has not been made implies that the member concerned believes that it is able to judge for itself whether the other party has made a prima facie case. however, no member is free to determine for itself whether a prima facie case or defence has been established by the other party. that competence is necessaril

y vested in the panel under the dsu, and not in the members that are parties to the dispute.”38
(i) the admissibility of non-requested information
in us-shrimp (ds58), the appellate body once again stresses the broad discretion vested in panels by the dsu. it states in pertinent: 39
“the comprehensive nature of the authority of a panel to ‘seek’ information and technical advice from ‘any individual or body’ it may consider appropriate, or from ‘any relevant source’, should be underscored. this authority embraces more than merely the choice and evaluation of the source of the information or advice which it may seek. a panel's authority includes the authority to decide not to seek such information or advice at all. we consider that a panel also has the authority to accept or reject any information or advice which it may have sought and received, or to make some other appropriate disposition thereof. it is particularly within the province and the authority of a panel to determine the need for information and advice in a specific case, to ascertain the acceptability and relevancy of information or advice received, and to decide what weight to ascribe to that information or advice or to conclude that no weight at all should be given to what has been received.
it is also pertinent to note that article 12.1 of the dsu authorizes panels to depart from, or to add to, the working procedures set forth in appendix 3 of the dsu, and in effect to develop their own working procedures, after consultation with the parties to the dispute. article 12.2 goes on to direct that ‘panel procedures should provide sufficient flexibility so as to ensure high-quality panel reports while not unduly delaying the panel process’.
the thrust of articles 12 and 13, taken together, is that the dsu accords to a panel established by the dsb, and engaged in a dispute settlement proceeding, ample and extensive authority to undertake and to control the process by which it informs itself both of the relevant facts of the dispute and of the legal norms and principles applicable to such facts. that authority, and the breadth thereof, is indispensably necessary to enable a panel to discharge its duty imposed by article 11 of the dsu to ‘make an objective assessment of the matter before it, including an objective assessment of the facts of the case and the applicability of and conformity with the relevant covered agreements … .’
against this context of broad authority vested in panels by the dsu, and given the object and purpose of the panel's mandate as revealed in article 11, we do not believe that the word ‘seek’ must necessarily be read, as apparently the panel read it, in too literal a manner. that the panel's reading of the word ‘seek’ is unnecessarily formal and technical in nature becomes clear should an ‘individual or body’ first ask a panel for permission to file a statement or a brief. in such an event, a panel may decline to grant the leave requested. if, in t

he exercise of its sound discretion in a particular case, a panel concludes inter alia that it could do so without ‘unduly delaying the panel process’, it could grant permission to file a statement or a brief, subject to such conditions as it deems appropriate. the exercise of the panel's discretion could, of course, and perhaps should, include consultation with the parties to the dispute. in this kind of situation, for all practical and pertinent purposes, the distinction between ‘requested’ and ‘non-requested’ information vanishes.
in the present context, authority to seek information is not properly equated with a prohibition on accepting information which has been submitted without having been requested by a panel. a panel has the discretionary authority either to accept and consider or to reject information and advice submitted to it, whether requested by a panel or not. the fact that a panel may motu proprio have initiated the request for information does not, by itself, bind the panel to accept and consider the information which is actually submitted. the amplitude of the authority vested in panels to shape the processes of fact-finding and legal interpretation makes clear that a panel will not be deluged, as it were, with non-requested material, unless that panel allows itself to be so deluged.”
(iii) summary and conclusions
as noted above, pursuant to art. 13 of the dsu, the initiative to seek information and to select the source of information rests with panels. art. 13 of the dsu enables a panel to seek information and technical advice as it deems appropriate in a particular case. this is a grant of discretionary authority: a panel is not duty-bound to seek information in each and every case or to consult particular experts under this provision. furthermore, this authority embraces more than merely the choice and evaluation of the source of the information or advice which it may seek. a panel's authority includes the auth