Voorbeeld: consumptie of 25 Households
Data on 25 households
Impact of income (X1) and wealth in stocks (X2) on private consumption (Y) (in
€1000)
Yi = 0 + 1X1i + 2X2i + ui
Coefficients measure the impact of a 1 unit increase of an X-variable on
the mean value of Y, holding the values of the other X-variables
constant
It measures the net or direct effect of an X on Y
Short results OLS-estimation
1
, 2
2 σu
2. Precision of OLS estimators σ β = 2 2
σ X ( 1−r X )
Y Coef. Std. Err. t P>|t| [95% Conf. Interval]
X1 en X2 moeten X1 .3318305 .1721011 1.93 0.067 -.0250853 .6887462
onafhankelijk zijn
X2 .1257858 .037688 3.34 0.003 .0476257 .2039458
van elkaar =
ceteris paribus _cons 36.79008 17.29449 2.13 0.045 .9235081 72.65665
Hoe > spreiding rond X: hoe zekerder we zijn van de parameters
Goodness-of-fit?
Do we have a good model?
2 SSM SSR
R-squared R = =1−
SST SST
Do we have a better model? (comparing)
3 important conditions on using R-squared
1. Sample (size) must be the same
2. Dependent variable must be the same
3. Number of estimated parameters must be the same
. reg Y X1 X2
Source SS df MS Number of obs = 25
F(2, 22) = 42.71
Model 126186.655 2 63093.3276 Prob > F = 0.0000
Residual 32501.9575 22 1477.36171 R-squared = 0.7952
Adj R-squared = 0.7766
Total 158688.613 24 6612.02553 Root MSE = 38.436
SSR
N−k ( N−1 )
2 2
Adjusted R-squared Adj . R =R =1− =1−( 1−R 2)
SST N −k
N −1
Corrects (penalizes) for the number of estimated parameters: zorgt ervoor
dat je niet oneindig parameters opneemt: hoe > k hoe < adjusted r²
Conditions
1. Sample (size) must be the same
2. Dependent variable must be the same
How to work with STATA
Import first row as variable names
Data editor
Sum
. sum
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller audecloetens. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $7.10. You're not tied to anything after your purchase.