An effect whereby a trend or tendency in cost, demand, etc., is maintained incrementally so that it becomes, or appears to become, irreversible; also in extended use.
Origin
1950s.
Definition of ratchet effect in US English:
ratchet effect
noun
Economics
An effect whereby a trend or tendency in cost, demand, etc., is maintained incrementally so that it becomes, or appears to become, irreversible; also in extended use.