Hi!
I am new to this forum and looking for some advice please. I have run a conditional logistic regression analysis using discrete choice data. The coefficients from the output will be used to input into a separate analysis. For various reasons, there are two further things I want to try but am unsure if I can do this in STATA and if so, how. Any help would be appreciated.

My initial command looked something like this:

clogit choice var1_low var1_med var1_high var1_vhigh
var2_low var2_med var2_high var2_vhigh var3_low var3_med var3_high var3_vhigh, group(obsid)
  1. I want to rerun the regression analysis with two levels of the categorical variable held constant - and re-estimate the other values based on this. So for example, if I have low, medium, high, and very high as my levels, initially I used very high as my reference and estimated coefficients for the other levels of the variable. Is it possible to hold low and medium constant and estimate coefficients for high and very high?
  2. Also it is possible in the regression to explore rather than having coefficient weights for each categorical level, to fit an exponential function between the best and worst levels for each variable? If so, how?

Thanks in advance!