True or False:

1. (i)An estimator is unbiased, if its expected value across di erent samples equals to the true value of the parameter.
2. (ii)OLS estimator is always unbiased.
3. (iii)We can use n1 ni=1 u2i to estimate the error variance 2 because it is unbiased.
4. (iv)If the sample size increases, we can have a better estimates of sd(0) and sd(1).