Programming the statistical procedures from SAS

2 stage regression

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Contributor
Posts: 72

2 stage regression

I want to run second regression from the predicted value of first regression. I have made it on this paper in order to understand it. Bdr is the dependent variable in first regression and in the second stage the value from first regression is used as predicted bdr as regressor. KakaoTalk_20161213_121417352.jpg

Respected Advisor
Posts: 4,756

Re: 2 stage regression

Use an OUTPUT statement in the first regression to get the predicted values into a dataset and use that dataset to run the second regression.

PG
Contributor
Posts: 72

Re: 2 stage regression

Can you explain more how to connect output from first regression with second regression.
Super User
Posts: 18,601

Re: 2 stage regression

Regression from step 1 creates a data set called reg_results

Pass that to your second regression. 

 

Proc glm data=SASHELP.class;

model weight = age height;

output out=reg_results p=Predict r=Resid;

run;quit;

 

proc glm data=reg_results;

model = ...;

 

 

Contributor
Posts: 72

Re: 2 stage regression

I have used following regression but it gives an error as shown in Picture. Screenshot 2016-12-14 18.06.36.png

Proc glm data=want1;
model bdr= fam EBITDA_TA MTB LNTA FA_TA RD_TA stdd;
output out=results p=Predict r=Resid;
run;quit;


proc glm data=results;
model cum= predict(bdr) EBITDA_TA MTB LnTA LnTA2 FA_TA RD_TA stdd assmat;
run;

Super User
Posts: 18,601

Re: 2 stage regression

Predict(bdr) -> what is this supposed to represent? 

 

I don't think it does does what you think it does. 

Contributor
Posts: 72

Re: 2 stage regression

predict(bdr) is the predicted value of bdr which i suppose to get from first level regression. then use that in the second regression as predicted value of bdr.
Super User
Posts: 18,601

Re: 2 stage regression

As I said, it's not doing what you think. 

 

Review your OUTPUT statement from the previous step. 

P=Predict -> what do you think this portion does? 

 

 

 

 

Contributor
Posts: 72

Re: 2 stage regression

i think it will predict all value of all the variables. moreover i do not understand r=Resid.
Super User
Posts: 18,601

Re: 2 stage regression

Like I mentioned, not what you think. 

 

It it creates a predicted variable called PREDICT. The residuals (predicted - actual) are stored in a variable called Resid. 

Open the dataset and examine if manually or run a proc contents and explore the variables there. 

 

Proc contents data=reg_results;

run;

 

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