The model rules in the Draft Common Frame of Reference (DCFR), as any other body of legal rules, in force or simply proposed, naturally have the intention of affecting, in the desired direction, the behavior of the relevant parties subject to them. Thus, it seems, at least prima facie, wise to consider the tools in our possession in order to get some estimate of how the latter would likely respond to the rules. In recent years, social scientists in several disciplines (economics and psychology primarily) have studied human interaction in contracting and similar environments. They have studied such types of behavior both in laboratory settings, but also in real-world markets using rigorous empirical techniques.
In this respect, the model rules in the DCFR look somewhat lacking in terms of the interest in the existing empirical knowledge of its subject matter. The main empirical source of information for the DCFR seems to be comparative legal analyses of EU Law and the Laws of European countries. This is indeed useful, but in order to understand the potential effects that the legal rules may have on the behavior of contracting parties, and, eventually, on the markets that link them, one should not disregard the amount of empirical knowledge that has been accumulated in recent years on how real people interact in a variety of contractual settings.
This importance of empirical knowledge for informed policy-making and for the design of legal rules does not imply that there is an Iron Law of empirical regularity, or that our current level of empirical understanding is perfect and final. It is undeniable that there is still much to learn empirically about contracting behavior. But if we take seriously –as I strongly believe we should- the impact of Contract Law on social welfare, empirical studies of contracting behavior, both in consumer markets and in firm-to-firm interaction, should carry some weight to assess legal solutions in Contract Law, and to craft them in an informed way.
—