The world has more than 200 states. Many states are federations and hence consist of multiple jurisdictions. Seemingly there is thus ample room for a social science approach to comparative law. In this perspective, each legal order produces a data point. Variance in the solutions adopted by different legal orders is used as evidence that a certain legal design causes greater justice, better political stability, higher welfare, or more equity. The results could motivate the strife for legal betterment, by the way of legal transplants. This Article cautions against the dangers inherent in this empirical enterprise. In a nutshell, the danger results from the fact that mere correlation (some jurisdictions are associated with some outcomes) is not causation (a difference in legal design is responsible for the difference in outcomes). Yet for choosing between alternative legal regimes, causation would be critical. The Article explains why comparative law is a conspicuously challenging source of empirical evidence. It discusses possible solutions.
