Some government economists view their home countries as immune to outside influence.
Conclusion
If nations' economies → must look beyond are to prosper national borders
Intermediate Conclusion
Economies are always open systems.
Evidence
International trade significantly affects prices and wages.
Evaluate
This is a pretty difficult argument to parse (and a lot of filler to ignore). Consider just the structural clues:
Some economists say _____ . But ______ ; _______ . Just as physicists did ___ , government economists must do ____ .
We can tell from "some ppl say .... But", that the first sentence is background/counterpoint, and the author's argument starts after the "But".
A colon / semicolon can often be a way to show that the 2nd half of a sentence supports the 1st half. We can also use the Support Test to think about whether that makes sense.
Why should we believe that economies are always open systems? Because, international trade affects prices and wages.
The last sentence begins with an analogy (Just as X, Y). Analogies are good fodder for Strengthening / Weakening, but they don't really have any place in the Sufficient Assumption universe, where the logic has to work 100%.
Since the conclusion is conditional we can think about whether we'd rather think about it as, , or as, .
Either way you slice it, the idea of "what prospering national economies" require or what could make it impossible for a national economy to prosper is a New Idea in the conclusion.
On Sufficient Assumption, new ideas in the conclusion must be in the correct answer.
We did kind of hear about looking beyond national border, when they told us about international trade.
Goal
We need something like,