Deriving the mean and variance of the least squares slope estimator in simple linear regression

preview_player
Показать описание
I derive the mean and variance of the sampling distribution of the slope estimator (beta_1 hat) in simple linear regression (in the fixed X case). I discuss the typical model assumptions, and discuss where we use them as I carry out the derivations. The derivations are carried out using summation notation (no matrices).

At the end, I briefly discuss the normality assumption, and how that leads to beta_1 hat being normally distributed. While I do discuss the real deal there, I go over it fairly quickly, as the main point of the video is deriving E(beta_1 hat) and Var(beta_1 hat).

Note that any time I use "errors" or "error terms" in this video, I am referring to the theoretical error terms (the epsilons) and not observed residuals from sample data.

Time stamps:

0:00 Brief discussion the simple linear regression model, assumptions, and some tools we will use.
2:58 Deriving E(beta_1 hat)
5:06 Deriving Var(beta_1 hat)
8:49 Discussion of normality of beta_1 hat.
Рекомендации по теме
Комментарии
Автор

Best channel ever. I love the content, the way you teach them, and how well you breakdowns assumptions and connect topics. Excellent works. Thanks

jadaliha
Автор

I don't understand how sum((X_i - X_bar)^2) = sum((X_i - X_bar)*X_i)

andrei
Автор

I would love to see the same video for multiple regression (unbiaseness and variance of estimators)! Your explanations are very clear

HaineGratuite
Автор

Best explainatory video I have seen. Thank you for bringing dry book knowledge to life!

zhaofengzheng
Автор

Excellent lecture. Thanks so much for making rigorous concepts easy to understand.

valeriereid
Автор

Thanks so much, this was is always easy to follow and comprehend especially when trading with the *ASH STRATEGY*

jolenej.baxter
Автор

Why can we assume that the xs are fixed, in real life they vary?

opheliaschwuchow
Автор

can you demonstrate the variance of B0 please? Thanks for this explanation btw

elizabethqueen
Автор

I love your derivation videos. It's cool to see where the theory comes from :D

jgrtrx
Автор

Thank you so much for the super helpful video!!! I am so glad to find your videos whenever I get to struggle with statistics courses.

captainw
Автор

3:20 (xi-xbar) it should be variable why you consider it constant ?

yassinewaterlaw
Автор

very clear explanations bringing out the assumptions well

elizabethokello
Автор

Very very clean and clear explanation

God bless you sir!!🙏🙏🙏

xtjsjtm
Автор

Your explanations and presentation are perfect. Thanks brother!

seanmahoney
Автор

Thank you so much, I was really excited by your perfect explanation.

aminasadi
Автор

Yo I don't understand how you can equate sum[(X_i - X_bar)(Y_i - Y_bar)] = sum [(X_i - X_bar)Y_i] is this not only true is Y_bar is exactly equal to zero. The denominator has the same problem. except with Xbar.

andrewhughes
Автор

I want same explain ation for matrix notation


I am also interested in logistics regression and estimating se of its coeff.

Can you help ?

xtjsjtm
Автор

Bo(intercept)and B1(slope) are constant values for a certain sample.What does taking mean of those B0 and B1 mean?

gagangayari
Автор

This is excellent. What program do you use to produce this?

NazirulHzm
Автор

Has anybody found a video like this for the regression model where the y-intercept is assumed to be 0?

michaelsaia