Question 47·Hard·Inferences
In late April, City K began replacing high-pressure sodium streetlights with LED fixtures. In the following six months, the city reported a 30% decline in "nighttime street crime" compared with the same period the previous year. Internal memos indicate that one week before the lighting project began, the police department reclassified several minor offenses, including loitering, open-container violations, and certain noise complaints, as "municipal code violations" that are excluded from the "crime" statistics used in the report. During the period studied, the number of nightly patrol hours remained unchanged. The report attributes the decline entirely to improved visibility from LEDs. Therefore, ______
Which choice most logically completes the text?
For inference-completion (“Therefore, ___”) questions, restate the argument’s claim, then treat new details as potential limitations or alternative explanations. Here, ask whether the reported change could be caused by a change in measurement/definitions (what counts as “crime”). Prefer choices that accurately qualify the conclusion, and eliminate options that overreach (e.g., “entirely,” “no effect,” predictions about other time periods) or that ignore the key confounding detail.
Hints
Pay attention to the word "Therefore"
The blank must be completed with a statement that follows from all the information given, including details that might weaken the report’s claim.
Focus on the reclassification detail
If some incidents are moved into a category that is excluded from the crime statistics, what happens to the reported crime total even if behavior stays the same?
Separate “reported decline” from “real decline”
Ask whether the passage provides a reason the number could drop on paper without a true reduction in nighttime street crime.
Watch for overreach
Eliminate choices that treat something as proved, make predictions about daytime crime, or claim the decline is due entirely to one factor when the passage introduces another possible explanation.
Step-by-step Explanation
Identify the conclusion being evaluated
The report concludes that the entire 30% decline in nighttime street crime was caused by improved visibility from LED lights. The blank after “Therefore” should be completed with what most logically follows from all the information provided.
Use the key evidence that complicates the claim
The passage says that one week before the lighting project began, police reclassified several minor offenses as “municipal code violations” that are excluded from the crime statistics used in the report.
So some incidents that may have been counted as “crime” in the earlier period may not be counted as “crime” in the later period.
Draw the logical implication
If the definition of what gets counted as “crime” changed right before the comparison period, then a reported decline could happen even without a real decline in behavior. That creates an alternative explanation (a measurement/categorization change), so the report cannot validly attribute the decline entirely to LEDs.
Also, unchanged patrol hours only suggests enforcement intensity didn’t increase; it does not isolate lighting as the sole cause.
Select the choice that matches that implication
The best completion is the one stating that the decline may reflect a change in categorization rather than (or in addition to) a true reduction caused by lighting.
Therefore, the reported decline could reflect, at least in part, a change in how offenses are categorized rather than an actual reduction caused by the new lighting.