203 Measurement Error 10a Solutions IV as a Fix

This video explores how instrumental variables (IV) can correct attenuation bias caused by measurement error in econometric models. Measurement error leads to OLS underestimating true effects because the observed regressor is a noisy version of the truth, creating endogeneity similar to omitted variable bias and reverse causality. We revisit the core problem: the explanatory variable X becomes correlated with the error term U, violating a key Gauss-Markov assumption. Discover how IV acts as a filter, isolating the true variation in X by using an instrument correlated with the true regressor but uncorrelated with measurement error and the structural error. Learn why this powerful technique, typically introduced for other endogeneity issues, is also the solution for measurement error, provided a valid instrument is found. Visit AxiomTutoring.com for more resources and subscribe to @AxiomTutoringCourses for future videos.