Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down at the end of May, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: Odds ratio


From   Richard Williams <Richard.A.Williams.5@ND.edu>
To   "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu>, "statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu>
Subject   Re: st: Odds ratio
Date   Fri, 09 Apr 2010 15:15:35 -0400

At 01:38 PM 4/9/2010, Marcello Pagano wrote:
Bookmakers have no problem interpreting odds.
Why people go through all sorts of contortions to avoid odds when they
are as natural as probabilities is beyond me.
If you take m/n as your probability then m/(n-m) are your odds.  One is
easier than the other?  Very odd.

Odds aren't bad, but odds ratios are much harder. If you tell me the odds are 4, I know that is the same as an 80% chance of success. But, if you tell me the odds ratio is 4, that is much vaguer because there are an infinite number of ways to get such a ratio. It could be that the odds for the two things being compared are 4:1, 8:2, 20:5, .4:.1, etc. etc. etc. Unless I know what the odds are for one of the things being compared is, it is hard for me to have much perspective on what the odds ratio really means in practice.

And while I don't think odds are a hard concept, I personally still tend to convert them into probabilities.


-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
OFFICE: (574)631-6668, (574)631-6463
HOME:   (574)289-5227
EMAIL:  Richard.A.Williams.5@ND.Edu
WWW:    http://www.nd.edu/~rwilliam

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index