Before you contact us please do the following:

1. Install the most recent update to Stata. Type help update in Stata.
2. Install the latest version of SPost. For details, click here.
3. Check the discussion of the topic in our book.
4. Include only letters, numbers, and underscores in your value labels.
5. Check your descriptive statistics to make sure your variable are what you think they are.
6. Check our FAQ Page.

If you need to contact us, please follow these guidelines fully

We want to help, but last year SPost was downloaded 10,000 times and we hear from a lot of people. The following things make it easier and faster for us to help. Please follow these suggestions carefully.

1. Do not send large files or zip files since they could be rejected by the IU system.
2. Create a do file that generates the problem you are having.
3. The do file should have your last name (e.g., freese.do)
4. Log the output to a text file, not a smcl file (e.g., log using freese, text replace).
5. Start the file with the command: prwhich
6. Do not refer to specific directories. For example, do not include something like use c:\data\project3\sample.dta because it will not run on our machines unless we either edit your file or create your directory structure. The same is true if you use something like log using c:\data\project3\problem, text.
7. Include descriptive statistics for the variable used in the commands that cause a problem.
8. Include lots of comments to explain what is going on and what the problem is.
9. Your do file might look like this:

capture log close
log using scott_long, replace text
// scott long - 2007-06-24 (jslong@indiana.edu)
// prchange returns missing values for a logit model
prwhich
use scott_long_data, clear
// descriptive statistic look fine
desc y x1 x2
tab y
sum x1 x2
// logit model gives reasonable results
logit y x1 x2
// the change coefficients for x2 are miss
prchange
log close
exit

Thanks. Jeremy Freese and Scott Long