What are the properties of OLS estimators?
OLS estimators are BLUE (i.e.
they are linear, unbiased and have the least variance among the class of all linear and unbiased estimators).
Amidst all this, one should not forget the Gauss-Markov Theorem (i.e.
the estimators of OLS model are BLUE) holds only if the assumptions of OLS are satisfied..
What are the properties of the least squares line?
The Least Squares Regression Line is the line that makes the vertical distance from the data points to the regression line as small as possible. It’s called a “least squares” because the best line of fit is one that minimizes the variance (the sum of squares of the errors).
What are least square estimators?
The method of least squares is about estimating parameters by minimizing the squared discrepancies between observed data, on the one hand, and their expected values on the other (see Optimization Methods).
What are the properties of estimators?
Two naturally desirable properties of estimators are for them to be unbiased and have minimal mean squared error (MSE). These cannot in general both be satisfied simultaneously: a biased estimator may have lower mean squared error (MSE) than any unbiased estimator; see estimator bias.
What are OLS estimators?
In statistics, ordinary least squares (OLS) is a type of linear least squares method for estimating the unknown parameters in a linear regression model. … Under the additional assumption that the errors are normally distributed, OLS is the maximum likelihood estimator.
What happens if OLS assumptions are violated?
The Assumption of Homoscedasticity (OLS Assumption 5) – If errors are heteroscedastic (i.e. OLS assumption is violated), then it will be difficult to trust the standard errors of the OLS estimates. Hence, the confidence intervals will be either too narrow or too wide.