When are OLS estimators BLUE?
For Classical Regression Model the OLS or Ordinary Least Squares - estimators (or the betas) are BLUE (Best, Linear, Unbiased, Estimator) when :
- The regression is linear in the coefficients, it is correctly specified and has an additive error term.
- Mean of the error term is zero. (Include a constant term in the regression (B0 which will force the mean to be zero)
- The independent variables are not correlated with the error term. (If they are correlated then the betas will be biased.)
- Observations of the error term (the residuals) are not correlated with each other.
- The error term has a constant variance (Homoskedasticity)
- No independent variable is a perfect linear function of any of the other independent variable. (If this is true - multicollinearity will occur)
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Because his eyes are all messed up.
He titled his comeback album in 1973 "Ol' Blue Eyes is Back". The name stuck.
Frank Sinatra ---------------- See http://en.wikipedia.org/wiki/Frank_Sinatra
Frank Sinatra ------------ See http://en.wikipedia.org/wiki/Frank_Sinatra
They are still unbiased however they are inefficient since the variances are no longer constant. They are no longer the "best" estimators as they do not have minimum variance
Francis Albert Sinatra, a.k.a Frank Sinatra.
Because he had beautiful blue eyes made even more striking by his black hair and tanned face.
A rough estimation is in low few thousands. This is because their were hunted and classed as endangered by 1950s. The pre-whaling population is estimated to be around 350,000 …bur 88% of the Whales were killed and only a couple of thousand remain currently.
ANSWER Because he was a bright blue eyed man with a bright glance.
Ol' Blue Eyes Is Back was created on 1973-06-04.
Ole Black 'n' Blue Eyes EP was created in 2006.
Tornado Chasers - 2012 Ole Blue 1-4 was released on: USA: 1 October 2012