What makes a government more transparent? This is the core question of the proposed research. Over the past twenty years, “transparency” has become a watchword in the international policy community. Increasingly, transparency— accessibility and availability of government information by the public—has come to be viewed as having numerous important benefits such as curbing corruption and promoting good governance, economic development, and international cooperation. Recognizing these effects, many international organizations have endorsed transparency as a global agenda. At the same time, as a prerequisite for political accountability, government transparency has been an age-old fundamental concern in democratic theory. In sharp contrast to the importance of the issue, however, empirically systematic investigation of transparency is quite underdeveloped. By way of addressing this deficiency, I focus on the case of the Freedom of Information Acts (FOIAs) to explore the conditions for creating transparency. FOIAs represent one of the most comprehensive contemporary policy measures for promoting government transparency, and they have recently swept around the world. Based on my literature review, the existing FOIA research lacks three important perspectives: causal analysis that has global coverage; investigation into the causes of FOIA laws’ variable contents across countries; and addressing the impact of transnational factors in policy diffusion. My research addresses these three missing perspectives. The specific question of this project is as follows: What transnational and domestic factors explain the adoption and the strength of FOIA laws around the world? A “strong” FOIA here means one that covers a wide range of government institutions, has a fewer exemptions, includes strict enforcement mechanisms, and provides easy public access. I take an exploratory approach to examine the above question, since not much systematic global-scale study of this subject is yet available. While it may be preliminary, my goal is to assemble a comprehensive picture of the causes of robust FOIAs. For that purpose, I will take the following steps. First, I will create an original FOIA database of all countries in the world, coding the presence or absence of FOIAs as well as their strength. Second, using this database, I will conduct econometric analysis to identify factors that influence the passage and the strength of FOIAs, focusing on both international and domestic causes. Third, in order to check the plausibility of the statistical correlations revealed in my econometric analysis, I will carry out a “process-tracing analysis,” which provides narratives based on concrete cases. This research will benefit both scholarly and policy communities. Its main academic contribution applies to the study of transparency. To my knowledge, it will be the first systematic study with global coverage and perspective that analyzes factors contributing to the adoption and strength of FOIAs. Also, this research will enhance the policy diffusion literature as well as the study of political accountability. For the policy community, my original global FOIA database will provide a comprehensive reference on the state of the world’s FOIAs. Further, findings of this research will assist those who advocate government transparency—civil society groups, international organizations, and policy makers—to efficiently and effectively influence the policy-making towards their goals.