Two Forms of Proportionality. Substantive and Institutional

The essay draws and develops a distinction between two forms that the standard of proportionality can take: substantive proportionality and institutional proportionality. Building on this distinction, it sheds light on institutional proportionality in order to outline the conditions under which it may apply, in particular to the interaction between the judiciary and the legislature. From this perspective, the essay sets out the requirements that the standard of institutional proportionality imposes on judicial intervention in political decision-making, in order to determine the scope and intensity of legitimate judicial decision-making vis-à-vis other types of institutional action. On this basis, it draws on relevant doctrines and decisions of the Italian and German Constitutional Courts to illustrate the different ways in which judicial institutions may adjust the scope and intensity of their action to comply with the standard of institutional proportionality.Finally, the essay argues that the interaction between institutional proportionality and substantive proportionality provides important elements for reflecting on proportionalist adjudication in light of the theoretical challenges raised by Tsakyrakis in 'Disproportionate Individualism'.