This article uses cross-country data to empirically investigate through which channel legal origin can influence antitrust effectiveness. The evidence shows that the adaptability channel (legal flexibility) is more important for explaining antitrust effectiveness than the political channel (authority independence). The evidence also suggests that countries in which a judicial decision is a source of law will provide more legal flexibility and will adapt more easily to changing economic circumstances. They will therefore also have better enforcement of antitrust rules. On the other hand, a legal tradition that takes no formal notice of legal precedent will make the competition environment much less predictable. To the extent that these findings are true, one would expect competition agencies in Common law countries to perform better than those in Civil law countries.
