Author Definition



The term “comity” is used in public and private international law to urge or demand that the institutions of one jurisdiction take the interests of one or more other jurisdictions into consideration in making legal decisions. Two levels of meaning may be relevant to competition law. One uses comity as a general concept to inform decisions. In this use it is not an element of enforceable law. In some countries, however, the concept has a second level of meaning in which it is an element of enforceable law that requires legal decision makers to take foreign interests into account in specific ways in specific situations.



The distinction between these two uses of the term often goes unrecognized, but it can be highly significant.

As a general concept: The comity concept is often overlooked or dismissed where it is not an element of enforceable law and therefore does not have a defined effect on specific legal decisions. It can, however, play important roles in understanding transborder dimensions of competition law. There are two such roles.

First, the idea of giving weight to the interests of foreign laws and institutions often influences relationships among competition law institutions. Respect for the interests of other jurisdiction is typically necessary where these institutions seek transnational cooperation - for example, where a competition authority in one state seeks information from a foreign competition authority. Some institutions pay significantly more attention to this concept than others, and there is often value in recognizing the weight given to comity considerations by the participants. For example, it can identify factors that are likely to influence the success or shape of negotiations regarding cooperation. Sometimes comity-based cooperation principles are embodied in agreements among the governments involved or between the relevant competition authorities themselves. For example, the competition authorities of the US and the EU are obligated by an international agreement to cooperate in specified ways in the sharing of particular types of information. Uses of this general concept by diverse states can also structure issues related to global competition law convergence and cooperation. This, in turn, will shape the future of competition law in the global economy.

Second, as discussed below, comity is often a conceptual basis for specific doctrines and rules in areas such as international private law (known in the US as conflicts of law) and the transborder jurisdictional reach of national laws. The concept may not be mentioned, but awareness of its content and roles often helps interpret and predict the application of specific rules.

As an element of applicable law: The general comity concept described above is an element of applied law in several contexts relevant to competition law.

 Jurisdictional reach of antitrust laws It has been particularly prominent in shaping the jurisdictional reach of US antitrust law. For several decades after the Second World War its role was central in applying US antitrust law beyond US territorial borders. Its role has diminished significantly since then, but decisions from that period still influence outcomes in US courts. Moreover, its influence has molded thinking in many countries about the role of the US in the global antitrust law arena.

The basics of this story are necessary for grasping the role of comity in the US antitrust context. Near the end of World War II US courts claimed jurisdiction over conduct outside the United States that caused harm either within the US or to certain US interests. The claim extended the reach of US antitrust laws beyond what had previously been accepted as legitimate under international law. As a result, many states rejected the legitimacy of the jurisdictional claim, and some protested vigorously that it represented an attempt by the US to force other countries to accept “US capitalism”. Nevertheless, the US government vigorously promoted antitrust law as a means of protecting competition and thereby averting concentrations of economic power that were thought to have led to the disasters of the first half of the 20th century.

Responses to US jurisdictional claims led US courts to turn to the concept of comity to limit the reach of US claims. In this context, it played a central role from the 1960s into the 1990s. The courts applied a balancing of interests test in which they were expected to weigh the potential harm to a foreign state from application of US law against the interests of the US in applying the law. In 1994 the US Supreme Court curtailed the role of the comity concept, holding that it would not curtail US jurisdiction unless its application would create a “true conflict” with the law of another jurisdiction. Courts have differed in assessing the current status of the comity principle. In a 2018 case the US Supreme Court declared that US courts should give “respectful consideration” to a foreign jurisdiction’s interpretation of its own laws, but that they are not bound by that interpretation. The courts have also referred to the comity principle in considering the extent to which US pretrial discovery procedures can demand presentation of foreign materials in US courts.

Comity concerns were incorporated into a Federal statute in 1982, and this legislation remains the primary basis for determining the reach of US antitrust law. The US also has agreements with some foreign countries that include a role for the comity principle.

Jurisdictions outside the US seldom refer to the comity concept in determining the reach of application of their competition laws. They typically rely on statutes to delimit the range of jurisdictional competence of their courts. The comity concept is, however, often implicit in the relevant statutes.

There are many reasons for the differences between principles of extraterritorial application of the antitrust laws in the US and in most other countries. Two factors are prominent: 1) The concept of “jurisdiction” in the US legal system is exceptionally broad, and it provides courts with the authority to impose obligations on litigants for failure to comply with a court’s dictates. Few other jurisdictions provide courts with such extensive authority and discretion in applying their laws extraterritorially, and 2) US courts are authorized to “make law” in ways that are seldom found outside the US - i.e., their decisions regarding jurisdiction are understood as law and evaluated accordingly.

 Private international law (conflicts of law) In numerous countries, the comity principle is a component of the laws and principles governing the application of foreign law in their courts. These laws specify situations in which domestic courts must apply the law of a foreign jurisdiction or may not do so. In some jurisdictions the comity-based rules are specific, while in others they involve interest balancing by the domestic court. These principles are sometimes relevant to the application of competition laws.

 Positive comity agreements In addition to the basic concept of comity discussed above, there is a concept referred to as “positive comity” which occurs in a limited number of international agreements, typically bilateral agreements. Such provisions provide that on request of one party another party should apply its law to punish a violation of the requesting party’s competition law. Positive comity provisions are seldom applied.



David J. Gerber, Global Competition: Law, Markets and Globalization (OUP, 2010, 2011)

Joel R. Paul, The Transformation of International Comity, 71 Law & Contemp. Probs. 19 (2008)

Joel R. Paul, "Comity in International Law," 32 Harvard International Law Journal 1 (1991)

Jurgen Basedow, Limits and Control of Competition with a view to international harmonization (Kluwer, 2002)

William S. Dodge, International Comity in American Law, 115 Colombia Law Review 2071 (2015)


  • Chicago-Kent College of Law


David J. Gerber, Comity, Global Dictionary of Competition Law, Concurrences, Art. N° 12200

Visites 3210

Publisher Concurrences

Date 1 January 1900

Number of pages 500


Institution Definition

Principle applied in the field of international co-operation on competition policy. By negative comity, every country that is party to a co-operation agreement guarantees to take account of the important interests of the other parties of the agreement when applying its own competition law. By positive comity, a country may ask the other parties of the agreement to take appropriate measures, under their competition law, against anti-competitive behaviour taking place on their territory and affecting important interests of the requesting country.

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