At the same time, economists are increasingly being given the opportunity to help governments design new policies and regulations2. And, in this respect, we should bear in mind that carefully designed scientific experiments have been an engine of economic, technological, and social progress. Social experiments have become crucial to ensure that governments implement policies with a proven record of success3, that are based on evidence and not on prejudice or intuition. We are now in a position to create a virtuous circle that begins with the allocation of resources to the compilation of data and the provision of access to them, continues with the evaluation of public policies, and ends with the application of the findings to the design of policies. However, unlike medical trials, social experiments – large-scale, publicly funded randomised controlled trials – have not become the gold standard for the evaluation of public policy interventions. 1  Einar, L. y Levin, J. (2014) "The data revolution and Economic Analysis", Working Paper 19035 National Bureau of Economic Research (NBER) 2  Duflo, E (2017)"The Economist as Plumber" Richard T. Ely Lecture, American Economic review: Papers and Proceedings 2017, 107(5):1-26 3  Heffetz, O y List, J (2021) "Who's afraid of evidence-based Policymaking?" Artefactual Field Experiments 00739, The Field Experiments Website 1  In many cases, critics argue that such experiments are inherently unfair. Ironically, this resistance to experimentation could eventually lead to less progress and even less fairness.
Without evidence about what works best, governments end up effectively running a mass experiment on everyone, but without the appropriate controls and therefore without learning as much as they could do to improve their policies. In this regard, the "causal revolution" of the past 30 years has also been characterised by the increasing attention that researchers have devoted to justifying causal interpretation of their research findings. In parallel, the appearance of new data, together with new concepts to be measured and new measurement techniques, have multiplied the opportunities to provide convincing descriptive analysis, even in the absence of experimental data. The influence of these approaches has been immense and has given rise to empirical results capable of shaking the most entrenched beliefs of economists. The truth is that there are still wide disparities in data availability across countries. At one extreme there is Denmark and other Scandinavian countries, with a culture that encourages the use of public data by the research community for the common good. But, in most cases, even if public administrations are repositories of enormous wealth in the form of individual data, the administration that holds the data is not capable of exploiting their full potential. Analysing this data is not their main priority and information is usually scattered among various administrations that do not readily communicate with each other or are very reluctant to share their data, even with external researchers.