Organizations in a field converge on similar forms through coercion, imitation, and professional norms rather than efficiency.
DiMaggio and Powell's 1983 paper. Hospitals, universities and firms in a field converge on the same structures because of legitimacy pressure, not because the structures work — mimetic isomorphism is strongest under uncertainty.
In practice
- Every charity in a sector acquires an impact framework, a theory of change and a strategy day, because funders expect them rather than because they work.
- Four competing hospitals adopt the same electronic record because it is what a hospital has, and each finds it a poor fit in a different way.