[CWuestefeld]

Economics ... makes predictions (or prescribes courses of action; these are equivalent).

This is absolutely false, except at the micro level. In terms of policy, economics can only inform us of the relative costs of various alternatives. It cannot tell us which alternative is right.

Consider the question of free trade. Virtually every economist agrees that free trade improves total efficiency (viz the Law of Comparative Advantage). However, at the margins, it may harm some individuals. Economics cannot tell us if it is morally right to incur those individualized harms in order to improve the lot of the whole, nor what if anything we should do to make whole those who were affected.

Economics makes predictions, giving us insights. Our morals are then needed to prescribe courses of action.

[amalcon]

You are right. To prescribe a course of action is to make a prediction (that this action will lead to results in some way superior to alternative courses). The reverse, as you correctly point out, is not necessarily the case.