<p>@SimpleLife - A Ph.D. student will stay on a project for about 3 years and a Masters student will only have about 1 year (the coursework is the major part of 2 years). If I have a grant that has to produce results and every year I am retraining a new Masters student who never gets to the point of publishing (or just one publication), I will prefer a Ph.D. student who become more productive in the second and third years and then can help train new students. Of course a good Masters student is welcome but an equally good Ph.D. student is better.</p>
<p>Graduating Ph.D. students is important for getting tenure but more important than that is publications and Ph.D. student (and postdocs) are more effective at that.</p>