Using economics in competition law private enforcement litigation : judicial undervaluing of economic evidence, heuristic mechanisms of judicial decision-making and why some theories are more successful than others

Abstract

The starting point of the thesis is the hunch that judges in private Competition Law litigation cannot directly appraise (complex) empirical or theoretical economic evidence. Thus, the first question the thesis asks is whether this is true and if so, why this is the case. The answer, found with the help of behavioural psychology literature, is that economic evidence is indeed problematic for judges and, as a result, is systematically undervalued. The reason for this is that judges distrust evidence of a probabilistic, statistical or circumstantial nature and avoid making inferences from it, as such evidence is open-textured and allows the judge to imagine multiple subjectively plausible scenarios. Furthermore, the thesis shows that judges need to employ coping strategies in the form of decision making heuristics when having to appraise complex empirical or theoretical economic evidence. These heuristics form the basis for the content and explain the adoption and success of the economic theories employed in Competition Law litigation, such as the Chicago School in the US. In other words, those economic theories which make it easier for judges to navigate complex economic evidence are likely to be more successful. It is thus theories which are easier to apply, rather than those which are most precise, that tend to find favour with judges. Based on these findings I make the argument that the institutional characteristics of the legal system translate into a preference for a certain type of economics, which is based on simple, clearly-defined and axiomatic rules for categorising conduct. While I initially illustrate this claim by analysing the Chicago School in the US, I ultimately aim to show that axiomatic economics is present also in European national courts in private litigation. Lastly, the thesis analyses the implications of these findings for the relationship between public and private enforcement.