The EU has embraced the use of indicators as policy instruments for achieving common aims. One of the indicators, 'early school leaver' (ESL), depicts the proportion of young people leaving education and training prematurely. Initially defined as an education policy indicator, it has been transformed into a performance indicator measuring the targets of the current Europe 2020 strategy. In this article, we examine how the indicator works as "a policy instrument" at different levels of governance applying the conceptual tools provided by the policy instrumentation approach to unpack the components, pinpoint the political effects, and reveal the power relations they produce. Thus challenging the taken-for-grantedness of comparison as a way of knowing we have intended to shift the focus of discussion concerning the role of large-scale comparisons in education towards more productive directions: moving from problematisation and deconstruction of comparison to engaging with processes of measurement.