  In this paper I show the equivalence, under appropriate assumptions, of two
alternative methods to account for the presence of selection biases (also
called selection effects) in population studies: one is to include the
selection effects in the likelihood directly; the other follows the procedure
of first inferring the observed distribution and then removing selection
effects a posteriori. Moreover, I investigate a potential bias allegedly
induced by the latter approach: I show that this procedure, if applied under
the appropriate assumptions, does not produce the aforementioned bias.
