1  Effectiveness constitutes an evaluative framework for assessing performance against objective standards or expectations. When applied to international courts and tribunals, it normally implies an evaluation of judicial processes, outputs, and outcomes against specific criteria such as planned length and cost of proceedings, expectations about judgment-compliance, etc. The precise meaning of effectiveness of international adjudication is, however, subject to academic debate, and the actual use of the term by scholars, decision makers, and adjudicators has been inconsistent.

2  The effectiveness of international adjudication depends on a multiplicity of factors including: the jurisdictional structure of the adjudicative body itself, be it an international court, international arbitration tribunal, etc; its form of organization; the resources made available to it; the specific features of the adjudicative procedure; the quality of judges and court personnel; the strength of the enforcement machinery; and the external political support and legitimacy enjoyed by the relevant court or tribunal. Indeed, reforms in the operation of existing international courts and tribunals and much of the effort put into designing new international adjudicatory bodies are often aimed at improving the effectiveness of adjudicative bodies.

3  Discourse on the effectiveness of international adjudication is closely related to discourse on the role of international adjudication in international relations. Many of the reasons provided in support of resort to adjudication among methods for peaceful settlement of international disputes (Peaceful Settlement of International Disputes) are also provided in support of enhancing the effectiveness of adjudicatory bodies.

4  Although ‘effectiveness’ is a concept with specific meaning in a number of fields of international law, including the laws on remedies (Human Rights, Remedies; Remedies) and as a principle of interpretation of substantive rules of international law, denoting the centrality of facts and realities in understanding the contents of international law (Effectiveness), the use of the term as a performance-evaluating framework for international courts and tribunals is normally associated with an academic analysis of the operation of international adjudication bodies.

5  In the literature on international adjudication, the term effectiveness has been sometimes used loosely to convey expectations about specific aspects of the performance of international courts and tribunals, for example, that they process cases promptly, operate within reasonable budgetary constraints (Financial Aspects of International Adjudication), generate compliance with their decisions and contribute to the development of international law (Shany, 2014, 37–46). A recent publication has attempted to systemize such expectations and to arrange them in an evaluative framework developed in organizational sociology for assessing the performance of public and private organizations thus providing a goal-based or ‘rational system’ approach, which juxtaposes performance against stakeholder expectations (Shany, 2014, 13–14). According to this approach, an effective organization is one that meets both its official goals contained in its formally stated mission and its operative goals contained in the actual benchmarks set for evaluating the implementation of specific organizational policies (Perrow, 1961, 854–66), which may be the explicitly or implicitly articulated expectations of the relevant stakeholders. This goal-based approach allows for an exploration of the effectiveness of international courts and tribunals pursuant to multiple perspectives of different external and internal constituencies, who may project on adjudicatory bodies, at different points in time, their distinct sets of expectations. The approach thus offers a method for assessing actual performance against predefined goals, formulated at different levels of abstraction such as intermediate and ultimate goals (Shany, 2014, 18–9).

6  Among the challenges posed by the goal-based approach are the ambiguity of policy goals provided to international courts and tribunals, the possible existence of multiple goals that are not entirely consistent with one another, the need to determine the time frame in which goal attainment should be evaluated, and the need to rely on inaccurate rough proxies or other indicators for evaluating judicial performance against predefined goals. It is also difficult under this approach to draw comparisons between different international adjudicatory bodies, given their different goals, structures, procedures, and constituencies (Guzman, 2010, 177; Young, 1992, 163). Still, using this approach it is possible to track changes over time in the performance of the same judicial institution and/or in constituency expectations relating to it, and gain useful insights even from imperfect comparisons between international courts and tribunals belonging to the same family of institutions, eg human rights courts, economic integration courts, international criminal tribunals, etc.

7  There are several ‘generic’ goals of international adjudication bodies that can be assessed regarding attainment of judicial effectiveness. These include: (1) law interpretation and application or norm-support—international courts and tribunals are intended to generate information about the contents of international norms and the manner in which they should apply in particular circumstances, so as to guide and compel states and other relevant actors to comply with them (see eg, Art 19 European Convention on Human Rights and Fundamental Freedoms (1950); Art 3.2 World Trade Organization (‘WTO’) Understanding on Rules and Procedures Governing the Settlement of Disputes, Agreement Establishing the World Trade Organization (‘DSU’); (2) conflict resolution— international courts and tribunals are expected to facilitate settlement of the specific disputes adjudicated before them (see eg, Art 3.1 DSU) or contribute through judicial intervention to the solution of policy problems falling under their mandate (see eg, Preamble, Rome Statute of the International Criminal Court (1998) (‘Rome Statute’)); (3) regime supports— international courts and tribunals are expected to render support through their operation and the mere possibility of invoking their jurisdiction to the attainment of the goals of the legal regime in which they are embedded (see eg, Preamble, Agreement Establishing the Caribbean Court of Justice (2001); Preamble, Protocol on the Statute of the African Court of Justice and Human Rights (2008)); and (4) legitimizing international governance— through their operation and, at times, mere existence, international courts and tribunals legitimize the exercise of authority by public international law institutions whose activities they monitor, or support through dispute resolution or advisory functions (PCIJ Advisory Committee of Jurists (1920) 11; Franck, 1990, 61–2).

8  Some international adjudicatory bodies also have specific, idiosyncratic goals, such as promoting post-conflict reconciliation (see eg, Preamble, UNSC Resolution 955 establishing the International Criminal Tribunal for Rwanda), preventing the imposition of unilateral sanctions (McRae, 2008, 4–5) and harmonizing one legal regime with another (see eg, Art 6 Agreement on the European Economic Area (1992)). For more on the goals and functions of international courts (von Bogdandy and Venzke, 2014, 5–20).

9  It should be noted that organizational sociology has also developed approaches other than the goal-based approach to evaluate organization effectiveness that could also be applied to the study of international courts and tribunals. According to the ‘open system’ approach, the effectiveness of a public organization is measured in its ability to control, in relevant ways, its external environment and shape or modify the conduct of external actors through the outcomes it generates (Scott and Davis, 2007, 31). For international courts and tribunals, this implies that courts that influence the conduct of state and non-state actors and the dynamic of international relations are more effective than those which do not have as much impact. Such judicial influence can manifest itself, for example, in the deterrence of state officials or members of non-state groups from committing international crimes, in the agreement of parties to combustible conflicts to refrain from violence and resort instead to peaceful resolution through adjudication, and in instances of change in state conduct to comply with international court judgments.

10  Finally, according to the ‘system resources’ approach, an effective organization is one that succeeds in attaining sufficient resources for its long-term survival (Seahore and Yuchtman, 1967, 898). Applied to international courts and tribunals, it would seem that some long-standing courts and tribunals have been quite successful in attracting resources to continue their operations over the years (see eg, International Court of Justice (ICJ), Permanent Court of Arbitration (PCA), Court of Justice of the European Union (‘CJEU’), and the Iran-United States Claims Tribunal), whereas others have lost support and had to shut down (see eg, Southern African Development Community Tribunal (‘SADC’)). Some quasi-judicial institutions face serious budgetary problems (see eg, the Inter-American Commission of Human Rights and the UN Human Rights Treaty Bodies, which exercise quasi-judicial functions in the face of serious budgetary problems), and certain courts did not attract enough political and material support to get off the ground (see eg, the African Court of Justice and Human Rights). Ultimately, studies of effectiveness under both the goal-based approach and the system resources approach often focus on the extent to which international courts and tribunals were successful in satisfying the expectations of strategic constituencies (Pfeffer and Salancik, 2003)

11  Whereas the open system and system resources approaches are mostly descriptive in nature and focus on the reactions of third-parties to the activities of international courts and tribunals, the goal-based approach has a clearer normative dimension. It evaluates the compatibility of the actual performance of the assessed international court or tribunal against predetermined evaluative criteria. These criteria are the generic and specific goals of international courts or tribunals, which were set for them by the states that created them and/or other relevant stakeholders, and reflect expectations about what judicial bodies should do or justifications for such operations. Such a method of assessment is also compatible with the view of international courts as trustees of Member States and other constituencies, who perform for them important services and functions (Alter, 2008). The goal-based approach is thus particularly suitable for academic and policy-oriented research aimed at examining questions such as whether international courts and tribunals should undergo organizational or legal reforms, whether their continued operations should be further supported, and whether new international courts and tribunals should be created.

12  Note that the term ‘judicial effectiveness’ has to be distinguished from similar and related terms, which nonetheless convey a different meaning, ie, ‘judicial efficiency’ and ‘judicial cost-effectiveness’. The term ‘efficiency’ has been understood to capture the positive and negative costs, benefits, and externalities associated with the operation of the reviewed international court or tribunal (Druker,1990, 155), whereas the term ‘cost-effectiveness’ has been understood to capture the relationship between inputs and outputs in the operation of international courts and tribunals (van Dooren and others, 2015, 24). Thus, for example, the European Court of Human Rights (ECtHR) can be regarded as an efficient judicial institution, inter alia, because of its positive contribution to the entrenchment of democratic values in large swaths of the former Soviet bloc and due to the positive modelling it provided other geographic regions also interested in creating a regional human rights court. By contrast, the cost-effectiveness of the ad hoc international criminal tribunals for the former Yugoslavia and Rwanda has been questioned (see below).

13  Ascertaining whether the goals of international courts and tribunals were attained, or engaging in a cost-benefit analysis of their operation, invites an appreciation of their performance in two ways. Firstly, through examination of relevant judicial outputs or the direct products of their operation such as judgments and legal interpretations. Secondly, through examination of judicial outcomes or the direct and indirect effects of judicial outputs on the state of the world such as compliance with judgments and the ‘shadow effect’ of judicial operations on situations that were actually adjudicated and on other situations which were not actually adjudicated but fall under the purview of the potential jurisdiction of the relevant court or tribunal (Shany, 2014, 53).

14  Evaluating judicial outcomes from a judicial effectiveness perspective should be undertaken with a view to examining the potential of judicial operations for promoting goal-attainment—whether judicial decisions contribute to legal certainty in relation to the norms and legal questions the adjudicators address; whether the judgments issued develop the law in ways that are conducive to attaining the goals of the relevant courts or tribunals or of the legal regime in which they are embedded. Are they likely to be complied with, or, at least, generate pressure on the parties to adjudication to comply, eg through the expectations of third parties such as other states, investors, public opinion, and the like? Are the decisions of a sufficient quality which is likely to enhance the legitimacy of the court or tribunal in question (Legitimacy of International Adjudication)?

15  The answers to questions relating to the goal-attainment qualities of judicial outcomes can be only partly facilitated through review of quantitative outcome indicators, which constitute useful but imprecise proxies of judicial effectiveness. These indicators include data on judgment-compliance levels, statistics on the frequency of citations of court decisions, diffused support or legitimacy indexes such as the Eurobarometer, and levels of norm internalization. Qualitative indicators, such as self and peer assessments of the impact of judicial operations on changes in the actual practice of states and other stakeholders, on the development of the law in the relevant field and on the perceived legitimacy of judicial bodies and their overarching legal regimes, can also be utilized.

16  Another area of performance evaluation involves an assessment of the quality of the judicial process in terms of its duration, affordability, transparency, accessibility to third parties to litigation or inclusiveness, procedural fairness, etc. (Good Administration of Justice). Since judicial outcomes are a function of judicial processes, judicial effectiveness is likely to be significantly affected by the quality of the judicial process. Here too, both quantitative and qualitative indicators, such as data on the length and costs of adjudication and studies on party satisfaction with the process, may assist in evaluating judicial effectiveness.

17  Finally, process, output, and outcomes are influenced by the structural attributes of judicial bodies as well as the inputs into the judicial process, like the legal powers held by the relevant court or tribunal, its budget and personnel, its reputation for judicial independence, and the propensity of potential parties to resort to adjudication before it. The quality and quantity of such structural attributes can be evaluated through indicators, such as changes in the number of States Parties to the court’s statute, fluctuation in its caseload and an assessment of the quality of the judges, eg their level of expertise (Independence: International Adjudication; Impartiality: International Adjudication).

18  It is important to note in this regard that international courts and tribunals operate through ‘feedback loops’, meaning that judicial outputs influence subsequent judicial inputs and judicial processes. For example, repetitive failure by parties to adjudication to comply with court judgments may result in prospective parties being more reluctant to refer new cases to the tribunal. In the same vein, a judgment which marks a significant departure from international law doctrine might result in the withdrawal of states from the court’s statute. At the same time, a record of success in resolving difficult disputes increases the ‘legitimacy capital’ held by the court in question, raising, in turn, its profile and potential for impact on the practice of states and other stakeholders.

19  A key performance or outcome indicator, central to review of the effectiveness of international adjudication, has been the evaluation of party compliance with judicial decisions. A rich body of literature analyses compliance with the judgments of the ICJ (see eg, Llamzon, 2008; Paulson, 2004; Schulte, 2004; Charney, 1987), Inter-American Court of Human Rights (IACtHR) (see eg, Gonzalez-Salzberg, 2013; Bailliet, 2013), ECtHR (see eg, Hillebrecht, 2014; Anagnostou and Mungiu-Pippidi, 2014), WTO Appellate Body (see eg, Davey, 2009), and other international courts and tribunals (see eg, Carrubba and Gabel, 2013). Some of this literature also offers comparisons between records of compliance of different international courts and tribunals (see eg, Hawkins and Jacoby, 2010–11).

20  Compliance is an important proxy for evaluating judicial effectiveness because its existence represents a relatively direct and easy-to-trace form of impact by the operation of an international court or tribunal on the conduct of a state or another international actor. Furthermore, evaluating compliance with judicial decisions can assist in gauging the reputation or legitimacy of an international court or tribunal in the eyes of the parties to adjudication. This is because there appears to be a causal relationship between the persuasive authority of judicial institutions (Venzke, 2013; Alter and others, 2018, 11–2) and the reputational harm associated with rejecting their decisions, on the one hand, and the propensity to comply with these decisions, on the other (Dothan, 2015, 11).

21  Still, one should note that the existence of ‘feedback loops’ (see para 18 above), and the attendant concerns about the reputational harm that may be inflicted upon an international court or tribunal were the parties to repeatedly fail to comply with its judgments, might lead judicial bodies to refrain from issuing controversial decisions or ordering intrusive remedies. Instead, in order to avoid confrontation with states and other important stakeholders in matters relating to important state interests or which involve sensitive cultural issues, they might adopt deferential doctrines, such as margin of appreciation, which reduce the likelihood of non-compliance (Shany, 2006, 922). Still, deference to states does limit the norm-support role of international courts and tribunals in providing specific guidance to states on the precise contents of international norms and addressing divergences between law and practice. Put differently, courts with high records of judgment-compliance may have only a modest impact on state practice, and vice versa (Shany, 2014, 126–30).

22  The experience of human rights bodies in addressing Ireland’s abortion laws and policies illustrates this point. In ABC v Ireland (2010), the ECtHR cited the acute sensitivity of the moral and ethical issues and the important public interests at stake (para 233), as the reasons for its decision that the regulation of abortion fell under the margin of appreciation of Ireland, hence requiring no significant change in the existing legal framework. By contrast, the Human Rights Committee, which issues Views that formally lack a binding status, did not extend to Ireland in its decision on Mellet v Ireland (2016) any margin of appreciation. Instead, it found Ireland’s sweeping legal ban on abortion to violate the International Covenant on Civil and Political Rights. Interestingly enough, Ireland complied with the Committee’s formally non-binding Views and proceeded to amend its constitution and to legalize abortion in the first weeks of pregnancy, and in some additional circumstances thereafter. It thus appears that despite the ECtHR’s superior legal powers and impressive record of judgment - compliance, its impact on the specific laws and practices of Ireland on abortion were less pronounced than those of the legally-weaker Human Rights Committee.

23  More generally, it should be observed that judgment-compliance is not necessarily correlated to all of the goals of international courts and tribunals. First, certain judicial decisions might be counter-productive from an effectiveness viewpoint, in that they fail to adequately promote the attainment of the overarching goals of the legal regime in which the courts or tribunals operate, such as ending impunity, trade liberalization, or maintaining international peace and security. In such circumstances, it can be claimed that non-compliance limits the adverse effects of ineffective judgments. Moreover, non-compliance or threats of non-compliance could incentivize judicial bodies to reconsider their approach to pending issues, in ways that could result over time in more effective judicial outcomes. The judicial dialogue between the CJEU and the German Constitutional Court relating to the protection of fundamental rights in the EU is sometimes offered as an example of how a threat of non-compliance by the latter has resulted in important reforms by the former (Davis, 2012).

24  Second, the short-term impact—on judicial effectiveness—of failure by the losing party in adjudication to comply with the judgment issued against it, may be offset by the long-term positive impact of the judgment on the development of substantive law in the specific field or on general international law, as well as on the practices of third parties. For example, although the IACtHR seems to enjoy relatively modest levels of judgment-compliance, its jurisprudence on topics such as the rights of indigenous peoples, amnesties for past human rights violations and the constitutional status of human rights has had a dramatic impact on the law and politics of Latin America (Hennebel, 2011; Soley, 2017).

25  Third, the ability of parties to adjudication to resolve the dispute between them does not necessarily depend on strict compliance with the judicial decisions issued. This is because the parties sometimes find creative ways to settle the case during litigation—a development not captured at all by data on judgment-compliance rate—or bargain around the judgment after it was issued (Coleman, 2003, 61–7; Paulson, 2004, 436).

26  As a result of this, some of the literature which sought to explore the correlation between structural aspects of international courts and tribunals, such as judicial independence and judicial effectiveness (see Posner and Yoo, 2005 and responses by Helfer and Slaughter, 2005 and Shany, 2012), can be criticized for treating compliance as a direct proxy for effectiveness, and not as one imperfect proxy among many. Still, collecting and analysing information on high or low compliance rates with court decisions is useful for effectiveness assessment—especially for evaluating case-specific impact (Helfer, 2014, 466–70) and overall legitimacy. It may, particularly, reveal changes in effectiveness over time and facilitate comparison between international judicial bodies that operate within similar structures and fields of law.

27  Over and above the question of judgment-compliance by the immediate parties to adjudication, international judgments may have an impact on the development of international law in general, and on specific branches of international law, in particular (see eg, Ginsburg, 2005, 631–40; von Bogdandy and Venzke, 2012; Helfer, 2014, 470–3). This law development function of international courts and tribunals is closely tied to some of their other functions: to engage in norm-support, including by providing more information on the content of international norms; to facilitate dispute avoidance, including by influencing states and other international actors to embrace internationally acceptable practices, which are less likely to give rise to confrontation with other states and international actors; and to advance the specific goals of the legal regime in which the court or tribunal operates, including by pursuing interpretations of the law informed by regime norms, values, and interests (Shany, 2014, 38–42).

28  Citations of international court or tribunal decisions by their domestic and international counterparts could serve as one proxy for assessing impact and perceived legitimacy (see eg, Pellet, 2013, 687–8; Voeten, 2010, 569–71; Leitão and others, 2019). Qualitative evaluation of the impact of specific international courts and tribunals on the development of legal doctrine and on policies adopted by third parties could also provide useful data for assessing their effectiveness (see eg, Blauberger and Schmidt, 2017; Viljanen, 2003). For example, the contribution of CJEU to the development of EU law, through doctrines such as direct effect, supremacy, proportionality, and general principles of community law has been regarded as an important indication of its effectiveness (see eg, Kaya, 2010, 223–6; Kelemen and Schmidt, 2014, 1).

29  The docket of cases pending before an international court or tribunal constitutes an important source of data for assessing its effectiveness. These include the size of the docket and the frequency of new submissions to the court or tribunal, compared to the frequency of issuance of new judgments, the diversity of parties to adjudication, the diversity off the issues adjudicated, and the length of time for cases to be processed from start to finish (see also Case Management). The utilization of a judicial body, or the lack thereof, might determine whether or not it can attain the goals of developing the law, promoting its implementation, resolving problems, and the like. Information on usage rates and modalities of usage could also shed light on the perception of the court as legitimate and effective in the eyes of its potential users (see eg, Helfer and Slaughter, 2005, 910; Schulte, 2004, 1. But see Elsig and others, 2017, 28).

30  A study of the docket of the ICJ over the years may provide interesting insights about its effectiveness. It has been remarked, for example, that the fact that the docket is dominated by cases brought unilaterally to the Court on the basis of compulsory jurisdiction provisions, without real prospects for prevailing or enforcing a favourable judgment, suggests that the parties to litigation are not genuinely interested in settling the disputes, but rather use the Court as part of their public diplomacy (Oda, 2000, 264). It can also be observed that a larger and larger proportion of the ICJ’s time has been devoted in recent years to maritime delimitation disputes, and that there have been significant fluctuations over the decades in the propensity of states, especially from the global South, to resort to adjudication before the Court. Such trends may represent perceptions of the Court’s utility by potential users—it may be regarded as a particularly effective forum for maritime delimitation cases and, at times, as an inhospitable forum for states from the global South (see eg, Amor, 2012, 5; Posner, 2004, 22–3; Rosenne, 2003, 117).

31  Some of the critical literature on the ICJ has focused in this respect on the post-South West Africa case period, during which the Court stopped receiving cases from developing countries, due to distrust in the Court by countries from the global South (see Mbengue and Messihi, 2016; Abi-Saab, 1996, 5). Such a disconnect between the Court and a key constituency adversely affected the institution’s perceived legitimacy during the relevant period, and prevented it from effectively attaining many of its goals vis-à-vis the said constituency. This disconnect and mistrust may have even led to the creation of an alternative jurisdiction to address law of the sea disputes (International Tribunal for the Law of the Sea (ITLOS); Wariobe, 2001, 43; Churchill, 2010, 146). In the same vein, the growing usage by developing countries of the WTO Dispute Settlement Mechanism has been viewed as a positive sign for the system’s overall effectiveness (Kim, 2017; Reich, 2018).

32  The ability of international courts to process cases from start to finish within a reasonable period of time is mostly an indication of their cost effectiveness. However, severe delays and backlogs may adversely affect the legitimacy of an international court in the eyes of its constituencies, could deter potential users from accessing it, and undermine its ability to satisfactorily attain its goals—ultimately, its effectiveness. Thus, for instance, the growing backlog of cases pending before the ECtHR in the first decade of the twenty-first century was perceived as a serious threat to its credibility and effectiveness (European Ministerial Conference on Human Rights, Resolution I (2000) para 16). Several reforms taken since then have succeeded in alleviating to some extent the Court’s backlog problem, though the time needed to process cases still remains long (Helfer, 2008; Cameron, 2013, 27).

33  The acceptance of a judicial body’s jurisdiction—through ratification of the treaty conferring jurisdiction upon it, acceptance of ‘optional clause’ type jurisdiction (see eg, Art 36 (2) Statute of the International Court of Justice (1945)), or ad hoc referral of disputes to adjudication—may be a helpful indicator of the Court’s utility in the eyes of potential parties to adjudication (Shany, 2016, 9). Such perceptions of utility or inutility can also be gleaned from reservations to instruments of acceptance of jurisdiction and from withdrawal and other forms of non-participation in the proceedings (Fry, 2010). Fluctuations over time in the level of acceptance of jurisdiction or across comparable international courts are also interesting, and may suggest an increase or decrease in the relevant court’s ‘legitimacy capital’ (Shany, 2014, 148).

34  Still, as with other structural features, such as budget and personnel, the legal powers assigned to a specific court or tribunal may be, at times, in an inverse relationship to its actual ability to regulate the policy space afforded to states and other international entities: It is easier for some states to join an ineffective institution than to assume burdensome restrictions attendant to membership in an effective court. In the same vein, withdrawal of states from the jurisdiction of an international court or tribunal may be explained as a reaction by certain states to its strong influence on certain policy problems and/or in certain regions.

35  Two recent examples of withdrawals, which may be regarded as reactions to effective adjudication are Venezuela’s withdrawal from the American Convention on Human Rights which entered into force on 10 September 2013, reacting to a series of decisions issued by the Inter-American Commission on Human Rights and the IACtHR against it, and Burundi’s withdrawal from the Rome Statute from 27 October 2017, reacting to the Court’s decision to investigate crimes which occurred in its territory. Arguably, in both cases, the Courts engaged in an implementation of their mandate, pursuant to the original expectations reflected in their constitutive instruments. The withdrawals stemmed not from failure to effectively meet the expectations of the State Parties that established the courts, but rather from political changes in the relevant states which rendered the courts’ decisions relating to them no longer politically acceptable.

36  In any event, the ability of international courts and tribunals to attain their goals depends to a large extent on their ability to exercise their legal powers or project their potential legal powers, known as the ‘shadow of the court’, in relevant circumstances (see eg, Alter, 2014, 19). Hence, although the level of acceptance of the jurisdiction of an international court is an imperfect proxy for its effectiveness, it is often an important variable creating the necessary conditions for effective application of judicial powers.

37  The phenomenon of backlash against international courts, which has generated much attention in recent years, has involved some high profile withdrawals from the jurisdiction of international courts such as the International Criminal Court (‘ICC’) and the IACtHR and, on a few occasions, even the termination of the operations of certain international courts, most notably, the SADC Court (see eg, Alter and others, 2016; Political Economy of International Adjudication). Such a backlash may be a reaction to an international court exceeding it goals as understood by the reacting states or international courts, or to the court effectively implementing the goals set for it, contrary to the expectations of the withdrawing entities who expected it to be toothless (see eg, Helfer, 2002, 1909–10).

38  Either way, withdrawals from jurisdiction or other forms of cooperation such as refusal to respect arrest warrants, non-appearance in legal proceedings, or refusal to refer cases to adjudication, can complicate the ability to attain judicial goals, may undercut the future effectiveness of the court or tribunal in question, and could result in inefficiencies in its operation, all being unnecessary negative externalities. At the same time, withdrawal or non-cooperation by certain states due to an international court or tribunal doing what it was supposed to do might render the operations of the relevant judicial body more credible and lead other states and stakeholders to rally to its defence. This, in turn, may even end up leaving the judicial body even stronger than it was before the negative reaction to its operation (Madsen and others, 2018, 217).

39  Among other indicators of effectiveness of international courts and tribunals one may note the financial resources made available to them as an indication of their judicial output and operational capacity, as well as a proxy for the degree of support they receive from their principal constituencies. The relationship between judicial output and the material resources made available to international courts and tribunals may assist in evaluating their cost-effectiveness (see also Economic Analysis of International Adjudication). Thus, for example, the ad hoc international criminal tribunals for the former Yugoslavia and Rwanda were criticized for the steep costs of their operation (Wippman, 2006, 861–2; Ingadottir, 2014, 599); and some concerns have been aired in relation to the ICC, given the high costs of its operation and the very limited number of judgments it issued in the first decade after its establishment (Ford, 2014, 100).

40  Finally, one may regard the perceived legitimacy of international courts and tribunals as an important indicator of their effectiveness as well, since perceptions of legitimacy tend to be correlated to actual success in goal attainment, and because legitimate courts are more likely to attract the support and cooperation from states and other international actors needed for them to further increase their effectiveness. Public opinion surveys, such as the Eurobarometer, are a useful quantitative research tool to measure diffuse support of judicial institutions which is an indication of the degree of sociological legitimacy they enjoy (Pollack, 2018, 164). Furthermore, public expression of support of international courts or tribunals by state officials and other key opinion shapers, or lack thereof, may also help evaluate their effectiveness and assist them in continuing to operate effectively in the future. For example, the legitimacy crisis encountered by the International Centre for Settlement of Investment Disputes (ICSID), due to a perceived pro-investor and anti-regulation bias in its arbitration awards, was expected to adversely affect the effectiveness of ICSID arbitrations, and, indeed, it has already led to several denunciations of the 1965 Convention on the Settlement of Investment Disputes between States and Nationals of Other States (Schreuer, 2010, 353–4; Bjorklund, 2018, 242).

41  The existing literature has sometimes referred to certain international courts and tribunals as effective or ineffective. While such designations are often impressionistic and not based on a robust method of assessment, they sometimes provide a useful indication of perceptions of, or reputation for, effectiveness. Such perceptions or reputation may prove to be a self-fulfilling prophecy, since states and other stakeholders might more readily support and accept the authority of judicial bodies deemed effective (Dothan, 2015, 49).

42  Among the international courts and tribunals referred to in the literature as particularly effective, one may note the ECtHR (see eg, Neier, 2012, 112; Bradley, 2013, 2) and the CJEU (see eg, Panke, 2011; Sweet, 2003, 18), both notable for their high volume of work and clear impact on domestic and regional law. Some of the literature also alludes to the WTO Appellate Body (see eg, Van Damme, 2009, 6; Elsig and others, 2017, 19) in positive terms, as effective in promoting the respective regime goals notwithstanding some difficulties encountered, and to the ICJ as an effective dispute resolution forum, which has contributed greatly to the development of international law (see eg, Couvreur, 2017, 264; Thirlway, 2016, 199). The impressive number of tried suspects before the International Criminal Tribunal for the former Yugoslavia has also been noted by scholars (see eg, Trahan, 2019, 31; Lamont, 2010, 128).

43  Less positive evaluations can be found in the literature dealing with ITLOS (see eg, Seymour, 2006, 2; Telesetsky, 2018, 180) and the ICC (see eg, Sadat, 2018, 386), mainly by reason of their relatively limited judicial output. Such assessments of effectiveness appear, however, to downplay the significance of the preventive role played by the two tribunals: ITLOS in mitigating harm in prompt release of vessel cases and the ICC by casting a shadow on many situations not leading to investigations or prosecutions (see eg, Yankov, 2001, 46; Jo and others, 2018, 209).

44  Effectiveness constitutes a framework for analysing the performance of international courts and tribunals. According to the goal-based approach such analysis juxtaposes judicial outcomes against goals—sets of explicit and implicit expectations for judicial bodies, formulated at varying levels of abstraction such as ultimate, intermediate, and maintenance goals, by a diversity of stakeholders (Shany, 2014, 18–19). Some goals, like norm-support, conflict resolution, regime support, and legitimization are generic, whereas other goals, such as ending impunity or harmonizing across legal regimes, are court specific.

45  A court or tribunal that succeeds in meeting the goals set for it is an effective judicial body, although the costs, benefits, and externalities involved in attaining the goals ought to be factored in to assess judicial efficiency and cost-effectiveness. Other approaches to assessing judicial effectiveness focus on impact and ability to attract support and resources needed for long-term survival.

46  Whereas some of the early literature on the topic of the effectiveness of international courts and tribunals focused on compliance as a central proxy for evaluating effectiveness, more recent literature has showed that compliance is merely one imperfect proxy for evaluating effectiveness, that compliance is not always correlated to the attainment of all judicial goals, and that, in the same vein, failure to comply with court judgments, like other forms of non-cooperation does not necessarily undermine the legitimacy and effectiveness of international adjudication.

47  Other useful proxies which can be used in effective analysis are impact of jurisprudence, docket size, acceptance of jurisdiction, available budget, and assessment of legitimacy. An examination of these and other relevant performance indicators —of a quantitative and qualitative nature—can provide a rather comprehensive picture of the degree to which an international court or tribunal attains it goals, impacts the practice of states and other stakeholders and enjoys support for its operations.

48  Although the examination of effectiveness is often difficult to execute with a degree of precision, it is nonetheless a useful tool to evaluate fluctuations in judicial performance over time, as well as to enable comparison between different international courts and tribunals that feature similar structure and perform similar judicial functions.

Yuval Shany