Constitution-makers often leave key issues undecided, or choose to defer certain issues for future resolution. This chapter examines this practice of constitutional ‘deferral', and its different variants in constitution-making processes worldwide – including in the form of abstract (rather than specific) constitutional language, express by-law clauses and conflicting constitutional provisions. It considers how deferral of this kind can help address both ‘decision' and ‘error' costs in processes of constitution-making, but also raise its own dangers of long-term delay or ‘burdens of inertia' in constitutional implementation. Finally, it considers what if any solutions there may be to this problem of recursive constitutional referral, including the idea of time-frames for deferred action, and judicial enforcement of legislative duties of constitutional implementation