Attribute non‐attendance in choice experiments affects willingness‐to‐pay (WTP) estimates and therefore the validity of the method. A recent strand of literature uses attenuated estimates of marginal utilities of ignored attributes. Following this approach, we propose a generalisation of the mixed logit model, whereby the distribution of marginal utility coefficients of a stated non‐attender has a potentially lower mean and lower variance than those of a stated attender. Model comparison shows that our shrinkage approach fits the data better and produces more reliable WTP estimates. We further find that while reliability of stated attribute non‐attendance increases in successive choice experiments, it does not increase when respondents report having ignored the same attribute twice.