In this paper, we emphasize the role of institutions as the underlying basis for economic and social activity. We describe and compare different institutional classification systems, which is rarely done in the literature, and show how to empirically operationalize institutional concepts. More than 30 established institutional indicators can be clustered into three homogeneous groups of formal institutions: legal, political and economic, which capture to a large extent the complete formal institutional environment of a country. We compute the latent quality of legal, political and economic institutions for every country in the world and for every year. On this basis, we propose a legal, political and economic World Institutional Quality Ranking, through which we can follow whether a country is improving or worsening its relative institutional environment. The calculated latent institutional quality measures can be especially useful in further panel data applications and add to the usual practice of using simply one or another index of institutional quality to capture the institutional environment. We make the Institutional Quality Dataset, covering up to 197 countries and territories from 1990 to 2010, freely available online.