Accreditation is a central element of the framework for research access to micro-data that currently is understood to be a barrier for transnational access. To better understand the nature and causes of the problem, and to devise potential solutions, we have mapped current arrangements across European countries. We identify similarities and differences as well as areas for improvement. Our key results are encouraging: almost all European countries do provide research access to their micro-data, and most of them allow non-national European researchers to access their data, though under varying conditions. However, some obstacles remain, and some of them require negotiation and coordination at policy-making levels. To overcome existing barriers, we propose some potential options for the future and concrete steps towards improvement, which if explored from now on, could substantially improve access while still ensuring safe and lawful conditions, and reducing the administrative financial burden of data providers
