b. Suppose there are two estimators (b2 and b2') of a true parameter, B2. The diagram below shows the density functions of two estimators, fi(62) and f(b2'). The true value of B2 is indicated on the horizontal axis. 12(62') (b) B2 i. What is the definition of "efficiency" in econometrics? ii. In the diagram, which estimator is more efficient, b2 or ba