The WDR explores the tremendous potential of data to improve lives. For the vision to be achieved, a new compact on data is necessary. The data revolution holds the promise of better decision-making, improved service delivery, and increased accountability and transparency in the public sector. However, restrictions to data access, sometimes compounded by a reluctance to share, and a growing awareness of the risks that come with data access and sharing, mean economies and societies are not harnessing the full potential of data.The national statistical system as producer and custodian of data sets of national importance is an integral part of the national data ecosystem and instrumental to the success of the data agenda.For decades, national statistical offices (NSOs) have played a central role in national information ecosystems. The compilation of macroeconomic indexes and business statistics have earned the NSO a central role in national economic planning. The decennial population and housing census and well￾designed national survey programs are still the main source of socioeconomic information in many countries. NSOs, as a result, have enjoyed a special position within government and in society as the main source of trusted information. The head of an NSO, widely known as the chief statistician, is in most countries the head of a professional service often called upon to explain statistical trends to the public.