The production of expert evidence in Brazilian arbitration often mirrors the domestic judicial model, diverging from the flexibility inherent to arbitration and from international standards, as highlighted by the ICC Task Force.

Introduction

The use of arbitration as an alternative dispute resolution method in Brazil has been a success: Based on data from the eight largest arbitral institutions, 376 new proceedings were filed in 2024, involving BRL 76 billion in dispute. The total number of ongoing Brazilian arbitrations in 2024 across those same institutions exceeded 1,200.[1]

The success, however, also brings a paradox: Part of the domestic arbitral practice began reproducing expert evidence procedures typical of Brazilian court litigation patterns. The recent ICC Brasil Task Force Report on Expert Evidence in Arbitration (ICC Brasil Task Force Report)[2] identified this phenomenon and called for a greater alignment of Brazilian arbitration practices with established international arbitration standards.

Arbitration in Brazil: Growing Pains

Arbitration in Brazil has flourished as a more flexible and more efficient alternative to courts, better suited to resolving mid- and high-complexity disputes. Part of this is explained by structural limitations of the Brazilian court system: Over 75 million cases are currently pending,[3] and the average duration of a civil lawsuit exceeds five years across all instances.[4]

On the other hand, the Brazilian approach for producing expert evidence in arbitration frequently reproduces the structures and formalities of court proceedings. This tendency is most visible in how expert evidence has been handled in Brazil with extensive use of the tribunal-appointed expert, alongside party-appointed experts. The reliance on tribunal-appointed experts tends to prolong arbitrations: Studies indicate that such experts in Brazil take, on average, approximately 10 months to produce an expert report[5] and that cases with a tribunal-appointed expert last, on average, 28 months longer than those without one.[6] In this context, the use of the tribunal-appointed expert undermines one of arbitration's key benefits: efficient resolution of disputes in terms of time and cost.

The Market for Lemons and the Excessive Use of the Tribunal-Appointed Expert

In the Brazilian court system, expert evidence is traditionally structured around the following stages: (i) the appointment of an expert by the judge (the Court Appointed Expert or Perito in Portuguese); (ii) the appointment of experts by each of the parties (known as Technical Assistants or Assistentes Técnicos); (iii) the submission of written questions by the parties, to be addressed by the Court Appointed Expert; and (iv) the issuance of an expert report by the Court Appointed Expert, followed by reports of the parties’ own experts commenting on that report. The cross-examinations of experts are rarely used in Brazilian court proceedings. 

This model reflects the typical logic of civil law systems and, in Brazil, is grounded in the Code of Civil Procedure, which does not impose on technical assistants a duty of impartiality or technical independence: "Technical assistants are trusted by the party and are not subject to impediment or suspicion."[7] The absence of impartiality or independence requirement for technical assistants impacts expert evidence, as it can cast doubt on the adequacy of their work. Is the technical assistant demonstrating the “technical truth” or merely acting as a “technical advocate” for one of the parties? This uncertainty, more pronounced in Brazilian courts but also present in arbitration proceedings, tends to pervade tribunal decision-making and, ultimately, could devalue the work of the parties’ technical assistants.

Economic theory provides a useful framework for understanding this issue, notably through the lemons problem.[8] In George Akerlof’s seminal article, “The Market for “Lemons”: Quality Uncertainty and the Market Mechanism”, the author demonstrates that when there is information asymmetry—that is, when the seller has better knowledge of the quality (and supposed defects) of its product than the buyer—the prospective buyer will only offer an average price, reflecting the uncertainty about the product quality. This may cause sellers of high-quality products to exit the market (as the average price falls below what they are willing to accept). The consequence is that only low-quality products (lemons) would survive in the market, sold at low prices.

By analogy, sometimes a court (or an arbitral tribunal) cannot fully observe the quality of the party-appointed technical assistants—that is, whether they are partial or not—which can produce an environment in which the average reliability of technical opinions presented to the tribunal is low. In this case, the arbitral tribunal occupies the position of the buyer in Akerlof’s model: To decide, it must evaluate the technical evidence but may lack sufficient information about the quality of that evidence. The court (or tribunal) therefore tends to discount the weight it gives to the experts’ work.

In this context, and as pointed out by the ICC Brazil Task Force Report, arbitral tribunals in Brazil often resort to appointing their own expert, in addition to the parties’ technical assistants, as a means of bridging the gap between technical opinions. This is a recurring feature of Brazilian arbitral practice: Empirical research estimates that 75% of Brazilian arbitrations involve a tribunal-appointed expert,[9] compared to 10% in international arbitrations.[10] The result is a less efficient outcome for the Brazilian arbitral process, when compared to international arbitration.

Conversely, international practice relies significantly on cross-examination of party appointed experts to “drill,” expose deficiencies and contradictions, and, in the end, seek the “truth of the matter” without the need to appoint a court appointed expert. This seems to be a more proven and efficient manner to attest quality and relevancy of the experts’ testimony, which has been tested and used for decades, and one that should be more widely adopted in local arbitrations. ICC Brasil Task Force on Expert seems to be leaning in this direction. 

The ICC Brazil Task Force on Expert Evidence: The Assistant Gives Way to the Expert

The ICC Brazil Task Force Report notes that domestic arbitration has been facing growing criticism regarding cost and duration, and also observes that the handling of expert evidence in many proceedings reproduces practices shaped by the Brazilian civil procedure model of judicial expert appointments, with arbitral tribunals tending to appoint “tribunal experts” to conduct the technical analysis of the dispute.[11] The report highlights that, while the appointment of a tribunal-appointed expert may be appropriate in specific circumstances, it should not become the default approach. Its use may give rise to undesirable effects, including the extension of proceedings (potentially by more than two years), the multiplication of evidentiary steps, increased costs, and the risk of an implicit delegation of decision-making responsibility to the tribunal-appointed expert.[12]

In response to this diagnosis, the report proposes arbitrations adopting the terminology “Party-Appointed Expert” (rather than the Brazilian denomination of “Party-Appointed Technical Assistant”) to describe the professional retained by a party to submit opinions and inform the tribunal on technical aspects of the dispute.[13] While the suggestion may appear purely semantic, it reflects a shift in how expert evidence is understood in Brazilian arbitration. Rather than treating party-appointed experts as commentators on the work of a tribunal-appointed expert, the terminology reinforces their role as protagonists in the technical debate, whose analyses are to be evaluated directly and critically by the arbitral tribunal and by the parties’ counsel.

Additionally, the report suggests the following measures to improve the efficiency of expert evidence, depending on the case:[14]

• Party-appointed experts should be retained at the outset of the arbitral proceedings, and the scope of expert evidence is to be defined at an early stage.
• Party-appointed experts should commit to independence and impartiality vis-à-vis the retaining party and should not yield to pressure when preparing their opinions, as their work is produced for the benefit of the arbitral tribunal.
• Expert reports should clearly identify points of agreement and disagreement, as well as matters not addressed. They should also include alternative scenarios, even in cases where the expert disagrees with the opposing party’s underlying assumptions or methodology.
• In preparation for the hearing, party experts should identify the disputed technical issues, so that the hearing can focus on what is genuinely in contention.
• Joint examination of experts (“hot tubbing”) should be considered, particularly in complex arbitrations.

By emphasizing the central role of party-appointed experts as well as their independence and impartiality, the ICC Brasil Task Force Report contributes to bringing Brazilian arbitral practice into alignment with contemporary international standards.

Optimizing Case Management

It is both desirable—and feasible—to change the trend in which Brazilian arbitration so often finds itself, with both party-appointed experts adopting polarized positions and driving a collectively suboptimal outcome in terms of efficiency. In line with the recommendations of the ICC Brasil Task Force Report, we understand that improving the expert evidence process in Brazil requires bringing it closer to the international arbitration model.

Successfully implementing ICC’s Task Force recommendations requires that each participant in the arbitral process changes the way it operates: the tribunal, the counsel, the parties, and the party-appointed experts:

• Arbitral tribunals benefit from technical analyses that are high-quality, independent, unbiased, and technically rigorous, while also maintaining an interest in procedural efficiency. In this context, it is important for tribunals (i) to clearly signal their expectation that party-appointed experts will act with independence; and (ii) to engage more actively—and at an earlier stage—with the contested technical issues, so that they can resolve them without resorting to a tribunal-appointed expert.
• Counsel should recognize that party-appointed experts bear an independent technical responsibility and that their primary role is to assist the arbitral tribunal. Credibility is a key asset for such experts and is closely linked, in the tribunal’s assessment, to their perceived impartiality. It is therefore important for counsel to take an active role in selection and engagement of the party-appointed experts, briefing them on the facts of the case, conducting preliminary interviews, and seeking their initial views on the disputed technical issues. This approach, while common in international arbitration, is not widely adopted in Brazil.
• The parties have an interest in efficient proceedings, decisions rendered by a qualified tribunal, and experts capable of translating counsel’s legal arguments into clear and persuasive technical analyses and conclusions. It is therefore important that parties participate actively in the expert selection process, assessing candidates not solely on price, but also on quality, subject-matter expertise, and experience.
• Party-appointed experts, as the individuals responsible for producing technical evidence, must be guided by independence and excellence, bearing in mind that their ultimate objective is to inform the tribunal. Their analyses should identify points of convergence and divergence with the opposing expert and evaluate technically defensible scenarios consistent with the retaining party’s legal arguments. Party-appointed experts should not defend positions that are technically unsound, as this undermines both their credibility and the interests of the party that retained them. Overstepping the boundaries of sound technical analysis is likely to be counterproductive, often exposing weaknesses to the tribunal. Finally, party-appointed experts should make it clear from the outset that their work will be conducted in accordance with the best practices applicable to the subject matter at hand.

Conclusion

Arbitration has been—for almost two decades—a credible and widely used mechanism for dispute resolution in Brazil. However, preserving its core benefits, particularly efficiency and flexibility, requires improvements in how expert evidence is produced and used, which depends on the conduct and incentives of all participants involved.

Aligning Brazilian arbitration practice more closely with international standards—by fostering greater independence of party-appointed experts, encouraging earlier and more active engagement by tribunals with technical issues, and adopting a more quality-driven approach to expert selection—should enhance both the reliability of technical evidence and the efficiency of proceedings. In this context, limiting the routine use of tribunal-appointed experts to truly exceptional cases would also help avoid unnecessary delays, increased costs, and the risk of diluting the tribunal’s central role in decision-making. 

In sum, a more disciplined and balanced approach to expert evidence would ultimately ensure that arbitration in Brazil continues to deliver high-quality, effective, and timely dispute resolution.

The views and opinions expressed in this article are those of the authors.

Read Past Raising the Bar Issues