Rationing

thumb|right|Romanian ration card, 1989

line of people waiting for goods or services on a first-come, first-served basis, or an area where such a line forms

mathematical study of waiting lines, or queues

travel demand management strategy

generic term for a number of proposed emissions trading schemes under which emissions credits would be allocated to adult individuals on an equal per capita basis, within national carbon budgets

day in which one is encouraged not to consume meat

consequences of climate change

a type of market failure