Environmental Economics

Apparently the National Center for Environmental Economics has great taste in literature

Will Wheeler, friend of Env-Econ and economist at the EPA's National Center for Environmental Economics was fishing for cheap attention* by posting the picture below on Facebook. 

*It worked

Our new "econometrics category"!

[name],

You may be right semantically, but the "odds ratio" seems to be common usage.

Thanks,

John W.

On 9/1/2011 12:48 PM, [name] wrote:

Good morning.  I have been reading your site about logistic regression and odds ratios.  I don’t mean to be rude, but I think I found a key error concerning odds ratios.  What is referred to there as odds ratio is actually just the odds. 

                http://www.appstate.edu/~whiteheadjc/service/logit/intro.htm

An odds ratio refers to a ratio of two odds.  An odds ratio of 2 (See the paragraph beginning “An interpretation of the logit coefficient…”) implies that one odds is twice as large as the other odds.  It does not imply anything about a probability.  In fact, every probability has its corresponding odds which could then be doubled to give an odds ratio of 2. 

Exactly what an odds ratio of 2 implies is still a bit vague to me.  I am still trying to understand it.  I think perhaps the marginal effects may be more useful, and your site has been helpful as I study marginal effects.  So thank you for that.