Principle of proportionality in administrative procedure

In this paper, principle of proportionality is considered as synonym of principle of reasonability. It comes from Argentinean Case Law where reference to principle of rationality rather than of proportionality is preferred. The same applies to Peruvian Law, which administrative procedure law mentions reasonability. Principle of reasonability or proportionality is relevant at the time of decisions as a consequence of previous procedure. At the bottom of the paper, some case precedent from Argentinean Supreme Court of Justice in which the criteria of reasonability related to procedural rules applied are explained.