Hello,

I am very new to Stata - I have tried reading around to solve my error but I am struggling! I am using StataIC 16.

I am trying to run a regression for log hourly wages on various variables, many of which are factor variables. I have downloaded data from the labour force survey.

Regression:

reg LGHOURPAY AGE b(5).DEGCLS7 b(1).EMPLEN b(1).ETHUKEUL b(0).FDPCH16 b(9).FORTYP15 b(2).FTPTWK b(8).GORWKR b(15).IN0792SM b(1).MARSTA b(1).MPNR02 b(2).PUBLICR b(9).SC10MMJ b(1).SEX b(6).SNGDEGB

This is my regression and I believe the b(). allows me to choose what base/ reference level for the factor variables. However, I am getting the "Factor Variables may not contain negative values" error code. I have looked and the "don't know" levels for each variable have group number of -9.

How would I overcome this problem?

Thanks!