Degressive or progressive proportionality is an approach to the allocation (between parties, regions, states, or other subdivisions) of seats in a legislature or other decision-making body. Degressive proportionality means that while the subdivisions do not each elect an equal number of members, smaller subdivisions are allocated more seats than would be allocated strictly in proportion to their population. The seats-to-votes ratio decreases for larger subdivisions.
This is an alternative to, for instance,
Degressive proportionality is intermediate between those two approaches. As a term it does not describe any one particular formula.