02-25-2017 03:40 PM
my data include two variables with 20,000 records. One is whether or not received a product sample and the other is whether use the product or other products after received the product sample. I wanted to calculate the odds ratio to conclude that the consumer who received the product sample would be 2 times likely to use the product than the consumer who didn't receive the sample. However the product has only 3% of market share among all the products consumers use.
how to solve the problem in SAS?
I'm very appreciative of any helps?
02-25-2017 04:21 PM
Here's a good quick reference, Paul Allisons thoughts on the issue
You can google with the following term to get more responses : Logistic regression rare events
02-27-2017 04:07 PM
Since you describe a 2x2 table, you could avoid fitting a model altogether and simply use PROC FREQ and request an exact estimate of the odds ratio with the EXACT OR; statement.