As we stated in the Introduction and as mentioned by David Marrani in his “Introductory remarks on comparative law and interdisciplinarity”, this book is the result of an ambitious project. Our initial aim was to assess the efficiency of legal instruments used to register real estate property transactions in order to provide legal certainty. We have addressed this issue through a multidisciplinary approach altogether combining legal with economic analysis and drawing a comparison between a Common Law country (using English and Welsh law) and a Civil Law country (France). As such, our project was also a project of comparative law in action, in similar sense as what is described by Esin Orücu.

This project was built on a bet for a new methodology and on an assumption. The bet was to test a methodologsy which we could call “monographic and comparative economic impact assessment of law”. The assumption was that legal certainty is deeply linked with local legal culture and is not a by-product of the standardisation of law and legal procedures. In this regard, this project is clearly a pilot project and should be assessed as such.

But to address these issues and to try to draw some lessons from this research project, we first have to come upstream and to recall its genesis as a reaction to the World Bank Doing Business reports. The methodology and results of the World Bank gave birth to the “New comparative economics”, a recent school within economics, and to the “Legal origins theory”,4 which led to hot debates among economists as well as interdisciplinary exchanges between economists and comparative lawyers. Therefore, our analysis should also be put in perspective within these academic debates.

These concluding remarks will then be organized around the answers to three successive questions. Firstly, what “New comparative economics” does to comparative law? Or more precisely, what harm “New comparative economics” and its subsequent theories, such as “Legal origins” but also the economic assessment of the quality of law through indicators, may cause to comparative law? Secondly, what economics could do to comparative law? This second question then leads to what we may call the “Economic Attractiveness of Law” paradigm, bringing up an attempt to build new methodologies to compare the economic efficiency of legal instruments and institutions.