This paper advocates likelihood analysis for regression models with me
asurement errors in explanatory variables, for data problems in which
the relevant distributions can be adequately modelled. Although comput
ationally difficult, maximum likelihood estimates are more efficient t
han those based on first and second moment assumptions, and likelihood
ratio inferences can be substantially better than those based on asym
ptotic normality of estimates. The EM algorithm is presented as a stra
ightforward approach for likelihood analysis of normal linear regressi
on with normal explanatory variables, and normal replicate measurement
s.