Westonci.ca is the ultimate Q&A platform, offering detailed and reliable answers from a knowledgeable community. Discover reliable solutions to your questions from a wide network of experts on our comprehensive Q&A platform. Discover in-depth answers to your questions from a wide network of professionals on our user-friendly Q&A platform.

Estimation of the IV regression model:
(a) requires exact identification.
(b) allows only one endogenous regressor, which is typically correlated with the error term.
(c) requires exact identification or overidentification.
(d) is only possible if the number of instruments is the same as the number of regressors.