Policymakers and researchers often cite the importance of government transparency for strengthening accountability, reducing corruption, and enhancing good governance. Yet despite the prevalence of such claims, definitional precision is lacking. As a consequence, approaches to measurement have often cast a wide net, in many cases tapping into the capacity of government institutions more generally, resulting in empirical findings that are ambiguous in terms of interpretation. This paper argues that the operationalization and measure of government transparency should be tailored to two main parameters of the phenomenon under investigation: the principals and purpose of the information. We advance a new measure of government transparency argued to be more suitable for the study of the role of government transparency with respect to probity. The data derive from a survey of public administration experts in 102 countries carried out by the Quality of Government Institute and allow for a more reliable analysis of the effects of transparency on reducing corruption, and the analyses suggest that an association indeed exists.