What is freedom? Can we measure it? Does it affect policy? This book develops an original measure of freedom called "Autonomy Freedom," consistent with J. S. Mill's view of autonomy, and applies it to issues in policy and political design. The work pursues three aims. First, it extends classical liberalism beyond exclusive reliance on negative freedom so as to take autonomous behavior explicitly into account. Second, it grounds on firm conceptual foundations a new standard in the measurement of freedom that can be fruitfully coupled with existing gauges. Third, it shows empirically that individual preferences for redistribution and cross-country differences in welfare spending in Organisation for Economic Co-operation and Development (OECD) countries are driven by the degree of "autonomy freedom" that individuals enjoy. By means of an interdisciplinary approach and a sophisticated econometric methodology, the book takes an explicit stand in defense of freedom and sets the basis for a liberalism based upon people's actions and institutions.