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Observed versus predicted cigarette use reported on the day just before study intake. NB = negative binomial; ZIP = zero-inflated Poisson; HUP = hurdle Poisson; ZINB = zero-inflated negative binomial; HUNB = hurdle negative binomial; cigarettes use was truncated at 20 for clarity. Not shown: a single endorsement of 40 cigarettes. Note: ZIP and ZINB are modeling structural and sampling zeros.
