xttobit what is the sentence length how long is a sentence in stata what is sentence length what is the sentence length for xttobit what does 0 mean in tobit why run xttobit why do i use random effects tobit model random effects sentence length model what is the sentence length limit can the marginal effects of xttobit be used for the sentence length model? why use xttobit to predict sentence length? what is xttobit sentence length what is the sentence length in xttobit what is the sentence length of a censored incarceration case? which is a sentence length limit what is the sentence length limit for a criminal case which sentence length is the lowest how to test for sentence length in the tobit system when is sentence length capped tobit model of sentence length