Which of the following is not a sample property of OLS?
a. the average of all residuals is zero
b. the sum of all residuals is zero
c. the covariance of x and y is on the regression line.
d. Sample covariance of each included variable and the residuals is zero
Consider the following econometric model
birthweight = beta0 + beta1 smoking + u
where birthweight is a baby's weight at birth in grams and smoking is a dummy variable indicating whether the mother was smoking during pregnancy (smoking = 1) or not (smoking = 0).
What does beta1 show?
a. the birth weight of a baby with a smoking mother
b. an estimate of the causal effect of smoking on birth weight
c. the causal effect of smoking on birth weight
d. the causal effect of birth weight on smoking
If MLR 1-4 hold, then OLS estimators are
unbiased and consistent
are unbiased and inconsistent
correct
equal to the population parameter
