II. Legal authority
Arbitration rules (ICSID Arbitration Rules, ICSID Additional Facility Rules, UNCITRAL Arbitration Rules) have no detailed provisions concerning expert evidence. The IBA Rules on the Taking of Evidence in International Arbitration (2010) are commonly used,3 sometimes as a nonbinding reference or guidance.4 A less commonly used guidance document is the CIArb Protocol for the Use of Party-Appointed Expert Witnesses in International Arbitration. Certain investment treaties authorize a tribunal to appoint an expert,5 sometimes with a qualifier that the parties do not oppose (sometimes jointly) the appointment,6 as did NAFTA.7
Dunkeld International Investment Limited v. The Government of Belize (II) PCA Case No. 2010-21, Procedural Order No. 2, 17 January 2011, para. 8.7; CMC Muratori Cementisti CMC Di Ravenna SOC. Coop. A.R.L. Maputo Branch and CMC Africa Austral, LDA v. Republic of Mozambique, ICSID Case No. ARB/17/23, Procedural Order No. 1, 8 December 2017, para. 15.1.
Italba Corporation v. Oriental Republic of Uruguay, ICSID Case No. ARB/16/9, Procedural Order No.1, 29 July 2016, para. 17.2; Tennant Energy, LLC v. Government of Canada, PCA Case No. 2018-54, Procedural Order No.1, 24 June 2019, para 8.1; Churchill Mining and Planet Mining Pty Ltd v. Republic of Indonesia, ICSID Case No. ARB/12/40 and 12/14, Award, 6 December 2016, para. 249; Global Telecom Holding S.A.E. v. Canada, ICSID Case No. ARB/16/16, Procedural Order No. 1, 13 June 2017, para. 1.4; Standard Chartered Bank (Hong Kong) Limited v. United Republic of Tanzania, ICSID Case No. ARB/15/41, Procedural Order No. 2, 11 October 2016, para 1.5; ACP Axos Capital GmbH v. Republic of Kosovo ICSID Case No. ARB/15/22, Procedural Order No. 1, 10 February 2016, para 15.6; Menzies Middle East and Africa S.A. et Aviation Handling Services International Ltd. c. République du Sénégal, ICSID Case ARB/15/21, Procedural Order No. 1, 30 October 2015, para 16.2.
Central America-Dominican Republic-United States Free Trade Agreement (DR-CAFTA), 5 August 2004, Article 10.24; Agreement Between the Government of Canada and the Government of the Republic of Benin for the Promotion and Reciprocal Protection of Investments, 9 January 2013, Article 36; Treaty between the Government of the United States of America and the Government of the Republic of Rwanda Concerning the Encouragement and Reciprocal Protection of Investment, 19 February 2008, Article 32; Mexico - United Kingdom BIT (2006), 12 May 2006, Article 20; Free Trade Agreement between the Republic of Korea and the Republics of Central America, 21 February 2018, Article 9.25; Colombia - Japan BIT (2011), 12 September 2011, Article 36; Agreement between the Government of Canada and the Government of the Republic of Moldova for the Promotion and Protection of Investments, 12 June 2018, Article 33; Agreement between Canada and the Republic of Serbia for the Promotion and Protection of Investments, 1 September 2014, Article 34; Canada - Côte d’Ivoire Foreign Investment Promotion and Protection Agreement, 30 November 2014, Article 33; Agreement between the Government of Canada and the Government of Burkina Faso for the Promotion and Protection of Investments, 20 April 2015, Article 35; Canada - Peru BIT (2006), 14 November 2006, Article 42; Free Trade Agreement between Canada and the Republic of Honduras, 5 November 2013, Article 10.39; Canada - Kuwait BIT (2011), 26 September 2011, Article 33; Agreement Between Canada and the Republic of Cameroon for the Promotion and Protection of Investments, 3 March 2014, Article 33; Agreement for the Reciprocal Promotion and Protection of Investments between the Argentine Republic and the United Arab Emirates, 16 April 2018, Article 31; Canada - Mongolia BIT (2016), 8 September 2016, Article 33; Free Trade Agreement between Canada and Peru, 29 May 2008, Article 839; Comprehensive Economic Partnership Agreement between Japan and the Republic of India, 16 February 2011, Article 137.3.
III. Party-appointed and Tribunal-appointed experts
Mobil Exploration and Development Inc. Suc. Argentina and Mobil Argentina S.A. v. Argentine Republic, ICSID Case No. ARB/04/16, Decisión sobre la petición de remoción del Sr. Nils Janson como perito experto del Tribunal presentada por la demandada, 23 March 2015, para. 1; Hrvatska Elektroprivreda d.d. v. Republic of Slovenia, ICSID Case No. ARB/05/24, Award, 17 December 2015, para. 41; Société Ouest Africaine des Bétons Industriels v. Senegal, ICSID Case No. ARB/82/1, Sentence, 25 February 1988, 25 February 1988, para. 9.06; Suez, Sociedad General de Aguas de Barcelona, S.A. and Vivendi Universal, S.A. (formerly Aguas Argentinas, S.A., Suez, Sociedad General de Aguas de Barcelona, S.A. and Vivendi Universal, S.A.) v. Argentine Republic (II), ICSID Case No. ARB/03/19, Award, 9 April 2015, para. 7; Abaclat and others (formerly Giovanna A. Beccara and others) v. Argentine Republic, ICSID Case No. ARB/07/5, Procedural Order No. 15, 20 November 2012, para. 11; Perenco Ecuador Limited v. Republic of Ecuador (Petroecuador), ICSID Case No. ARB/08/6, Interim Decision on the Environmental Counterclaim, 11 August 2015, para. 587.
IV. Independence, impartiality, transparency
A tribunal-appointed expert has to be independent from the parties, their legal advisors and the arbitral tribunal.11 Lack of independence of an expert could affect the right of an arbitrator to hear the case, but does not do so automatically12 (see Conflicts of Interest and Disqualification of Arbitrators).
V. Experts on applicable law
Expert evidence on both domestic law (usually of the host State) and international law is common in investment arbitration. Tribunals also accept expert evidence on the Applicable Law, whether domestic or international (see Applicable Law), in addition to the legal pleadings of the parties’ counsel.13 This is open to criticism because an expert submission may be conflated with the legal submissions of the counsel, which is inconsistent with general international law approach of separate roles of experts and counsel.14
VI. Joint statements
Party-appointed experts of like disciplines may be required to meet with each other in advance of the hearing and prepare a joint statement of matters agreed and disagreed.15 This technique serves to narrow the areas of disagreement between the experts and maximise the compatibility between their evidence,16 making it easier to process for the tribunal and the parties.
VII. Witness conferencing
Witness conferencing, or “hot-tubbing”, is a questioning of several experts of like disciplines at the same time, putting them in confrontation.17 This tool can be used to streamline the giving of expert evidence at the hearing by allowing the experts to directly challenge each other’s views at the hearing.18 CIArb Guidelines on Witness Conferencing in International Arbitration provide guidance on how to determine whether to deploy hot-tubbing and if so, how to design the procedure in a given arbitration.
VIII. Post-hearing involvement
In the arbitrations that allow post-hearing submissions, experts can be further involved, particularly for assessment and re-examination of the parties’ economic models for damages calculations. An expert’s testimony can be subjected to another round of review by the other party’s expert so that that party’s counsel are better able to identify the weaknesses in the expert evidence of the other side.19
IX. Previously published writings
Eli Lilly and Company v. Canada, ICSID Case No. UNCT/14/2, Final Award, 16 March 2017, para. 323; Philip Morris Brand Sàrl (Switzerland), Philip Morris Products S.A. (Switzerland) and Abal Hermanos S.A. (Uruguay) v. Oriental Republic of Uruguay, ICSID Case No. ARB/10/7, Decision on Jurisdiction, 2 July 2013, paras. 126.
Ashford, P., Article 5 – Party-Appointed Experts, in Ashford P., The IBA Rules on the Taking of Evidence in International Arbitration, pp. 105-120.
Ashford, P., Article 6 – Tribunal-Appointed Experts, in Ashford P., The IBA Rules on the Taking of Evidence in International Arbitration, pp. 121-127.
Blackaby, N. and Wilbraham, A., Practical Issues Relating to the Use of Expert Evidence in Investment Treaty Arbitration, ICSID Review, 2016, pp. 655-669;
Cremades, B., The Expert Witness in International Arbitration, in Betancourt, J.C. (ed.), Defining Issues in International Arbitration: Celebrating 100 Years of the Chartered Institute of Abritrators, p. 192.
Dragiev, D., Rationalizing Applicable Law in Investor-State Disputes in Absence of Express Choice of Law Under Article 42 (1) of ICSID Convention – Part II, Kluwer Arbitration Blog.
Foster, C., The Role of Adjudicators and the Role of Experts, in Foster, C., Science and Precautionary Principle in International Courts and Tribunals, 2011, pp. 126-182.
Khodykin, R. and Mulcahy, C., Article 5: Party-Appointed Experts, in Fletcher, N. (ed.), A Guide to the IBA Rules on the Taking of Evidence in International Arbitration, 2019, pp 279-322.
Khodykin, R. and Mulcahy, C., Article 6: Tribunal-Appointed Experts, in Fletcher N. (ed.), A Guide to the IBA Rules on the Taking of Evidence in International Arbitration, 2019, pp 323-360.
Singh, K., Chandran, S., Premkumar, S. and Foo, A., The “Additional Weapon”: Practical Tips for Effective Expert Conferencing in Arbitration, Kluwer Arbitration Blog.