BookmarkSubscribeRSS Feed
☑ This topic is solved. Need further help from the community? Please sign in and ask a new question.
NKormanik
Barite | Level 11

Please see the following quote:

 

When Maximum Likelihood Exp(Est) is less than 1, increasing values of the variable correspond to decreasing odds of the event's occurrence.

Q1:  Just want to make sure....  So, decreasing values of the variable correspond to increasing odds of the event's occurrence.

 

Q2:  Additionally, the further from 1 the variable is (on either side), the greater the effect.

 

Example:

X1 MLE(Est) = 0.7

X2 MLE(Est) = 0.4

 

X2 will have a substantially greater effect on the odds of event's occurrence.

 

Thoughts appreciated.

 

Nicholas Kormanik

 

(p.s. -- If you feel there is a more appropriate forum for this question, please let me know.)

 

1 ACCEPTED SOLUTION

Accepted Solutions
pink_poodle
Barite | Level 11
Assuming a linear relationship between x and outcome, it does not matter where x value is. Yes, decreasing x would associate with increased odds of outcome.

View solution in original post

8 REPLIES 8
pink_poodle
Barite | Level 11
It may be easier to think about it in percents. One unit increase in X1 associates with 30% decrease in the odds of the event. One unit increase in X2 associates with 60% decrease in the odds of the event. Therefore, you are correct, X2 associates with a greater negative effect on the odds of the event’s occurence.
NKormanik
Barite | Level 11

@pink_poodle 

 

Super.  But the specific question I'm requesting confirmation of in Q1 is:

 

True or false: If MLE(Est) < 1, decreasing the values of that variable correspond to increasing odds of the event's occurrence.

 

 

NKormanik
Barite | Level 11

A bit more clarification:

 

In the above example, let's look at X2 values.

 

X2 in our dataset ranges from 0 to 100.  Assume a fairly normal distribution.

 

Does it not matter where in the distribution the X2 value is?

 

I.e., X2 = 70 vs. X2 = 30.

 

If X2 MLE(Est) = 0.4, decreasing X2 in either of the above will amount to an increase in the odds of the event in question.

 

Please enlighten with your wisdom.

 

pink_poodle
Barite | Level 11
Assuming a linear relationship between x and outcome, it does not matter where x value is. Yes, decreasing x would associate with increased odds of outcome.
Ksharp
Super User
"True or false: If MLE(Est) < 1, decreasing the values of that variable correspond to increasing odds of the event's occurrence."
It is true I think. @Rick_SAS has wrote many bolgs about proc logistic . If you read his blog you would know the answer.

Basically, Yx+1 - Yx = beta(x+1 - x) => beta . Here Yx+1 - Yx = LOG( Px+1/(1-Px+1) ) - LOG( Px/(1-Px) ) = LOG( ODDS ).
Therefore ,Exp(Est)=Exp(beta)=Exp( LOG( ODDS ) ) = ODDS . if ODDS>1 they have the same direction, whereas vice verse .
Rick_SAS
SAS Super FREQ

In spite of the title and the notation in the OP's question, I don't this question is related to maximum likelihood estimations. It is merely a statement about interpreting the parameter estimate for a linear logistic model. How that estimate was obtained is irrelevant.

NKormanik
Barite | Level 11

@Rick_SAS @Ksharp @pink_poodle 

 

Correct!  Doing a Google and Google Scholar search to answer the question brings up LOADS of the math.

 

 

NKormanik
Barite | Level 11

@Rick_SAS @Ksharp @pink_poodle 

 

Thanks all.  Rick's article was helpful in pointing to a far better perspective viewing odds ratio:

 

plots=oddsratio(logbase=2 order=descending)

 

Wow!  What a difference!

 

sas-innovate-2024.png

Don't miss out on SAS Innovate - Register now for the FREE Livestream!

Can't make it to Vegas? No problem! Watch our general sessions LIVE or on-demand starting April 17th. Hear from SAS execs, best-selling author Adam Grant, Hot Ones host Sean Evans, top tech journalist Kara Swisher, AI expert Cassie Kozyrkov, and the mind-blowing dance crew iLuminate! Plus, get access to over 20 breakout sessions.

 

Register now!

How to Concatenate Values

Learn how use the CAT functions in SAS to join values from multiple variables into a single value.

Find more tutorials on the SAS Users YouTube channel.

Click image to register for webinarClick image to register for webinar

Classroom Training Available!

Select SAS Training centers are offering in-person courses. View upcoming courses for:

View all other training opportunities.

Discussion stats
  • 8 replies
  • 743 views
  • 7 likes
  • 4 in conversation