
Julia C. answered 04/28/21
Bachelors in English, Experienced SAT Reading Tutor
You can use context from the sentence to find the answers to each question:
For the first blank, the phrase "the failure of many economists to respond to them is astonishing" tells you that the "shortcomings" should be very obvious and hard to miss, to the point where it's surprising that economists ignore them. "Overlooked" has the opposite meaning of what this sentence indicates, as does "occasional." Overlooked or occasional shortcomings would be too easy to ignore.
For the second blank, we use the first sentence to tell us that "the standard economic model" has "shortcomings" which "many economists" refuse to address. This tells us their models/ideas/theorems are, for lack of a better term, "bad." For the second blank, we want to look for a negative term to match the tone of the passage, and "comprehensive" and "pervasive" are either positive or neutral. So you go with "improbable."