Even up to today, it is not uncommon that policies are ad hoc, based on individual
case studies, and/or without unambiguous scientific support. That said, policy
makers rather do not experiment with interventions in the real world if there may
be substantial irreversible adverse effects. Economic models (of various sorts)
allow policy makers to evaluate the effects of their policy interventions before
actually implementing them in the real world. Over the last couple of decades, not