Hi everyone!

I am new to statistics so I guess there is an obvious answer to this question, but I found it surprising:

I am researching the effect of creativity on submitted innovation ideas in an organization. My dependent variable is a binary variable (dummy) that is 0 if the respondent has not submitted any ideas and 1 if they have submitted one or several ideas.

One of the control variables is position. It is a categorical variable with 9 response items. In short: managers have submitted most ideas and the responding health workers have not submitted any ideas.

Here's the thing:

I have usually just told Stata to treat it as a categorical variable by including it as i.position. This will use the first category (managers) as a reference category. Doing this (almost) none of the categories came out significant.

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However, when changing the reference category to health workers (who submitted 0 ideas) all positions came out significant.

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Shouldn't the relationship between the different positions be the same regardless of which category is used as reference?


Another question:
When calculating the percentage of respondents from each position who have submitted ideas I find 89% of managers to have submitted ideas and 64% of physical therapists. However, in the regression results the physical therapists have a higher coefficient than managers (.6363 vs .5357). How can this be?