Theoretical (epistemic) virtues

When two competing theories or hypotheses explain or accommodate just the same data (and both are unrefuted), which should be preferred? According to a classical, purely formal confirmation theory, neither – each is confirmed to the same degree, and so the two hypotheses are precisely equal in epistemic status, warrant or credibility. Yet in real life, one of the two may be preferred very strongly, for any of a number of pragmatic reasons: it may be simpler, more readily testable, more fruitful or less at odds with what we already believe. The philosophical question is whether such pragmatic virtues are of no specifically epistemic, truth-conducing value, or are instead genuine reasons for accepting a theory as more likely to be true than is a competitor that lacks them.