underidentification.

A model's failure to determine a unique set of parameter values from its observations and restrictions.

Use it for

Words that belong together

• test for underidentification
• underidentification of a model
• underidentification test

On the page

The authors test for underidentification before interpreting the structural coefficients.

Adding more observations did not remove the model's underidentification.

Usage notes

Primary category: academic / formal / analytical. Lexical Type: Word. Forms: Usually uncountable; no ordinary plural in this sense. Commonness: uncommon (editorial estimate; not a corpus frequency statistic). Legacy lexical fields mirror sense 1; numbered fields keep each relevant meaning separate. Research distinction: CEMMAP paper directly read: inability to uniquely identify a parameter vector from moment conditions; rank condition below needed rank in the linear model. Order count alone is insufficient. Nonlinear first-order underidentification may involve failed rank condition despite local identification; qualification retained. Individually useful in research, criticism, methodology or conceptual analysis. Definitions and examples are original; no mood or intensity assigned to neutral analytical concepts. Commonness is an editorial estimate, not a frequency statistic. Writing functions: parameter recovery and identification, inference limited by nonunique model values.