In contrast, an '''endogenous variable''' is a variable whose measure is determined by the model. An '''endogenous change''' is a change in an endogenous variable in response to an exogenous change that is imposed upon the model.<ref name=Mankiw/>{{rp|p. 8}}<ref name=Chiang/>{{rp|p. 8}}
The term '''[[endogeneity (econometrics)|endogeneity]]''' in [[econometrics]] has a related but distinct meaning. An endogenous random variable is [[correlation|correlated]] with the [[Errors and residuals|error term]] in the econometric model, while an exogenous variable is not.<ref>{{cite book |first=Jeffrey M. |last=Wooldridge |authorlink=Jeffrey Wooldridge |title=Introductory Econometrics: A Modern Approach |___location=Mason |publisher=South-Western |edition=Fourth |year=2009 |isbn=978-0-324-66054-8 |page=88 |url=https://books.google.com/books?id=64vt5TDBNLwC&pg=PA88 }}</ref>
