Definition: Estimator Estimator is a formula or a rule that takes a set of data and returns an estimate of the population guantity(also known as population parameter) we are interested in e(X1X2r- Xn) Ka-fu Wong C2007 ECON1003: Analysis of Economic Data Lesson 1-13Ka-fu Wong © 2007 ECON1003: Analysis of Economic Data Lesson1-13 Definition: Estimator ◼ Estimator is a formula or a rule that takes a set of data and returns an estimate of the population quantity (also known as population parameter) we are interested in. θ(x1 ,x2 ,...,xn)