A city council implemented a new tax on sugary drinks. One year later, the obesity rate in the city dropped by 5%. The council concluded that the sugary drink tax successfully caused the reduction in obesity.
Match each alternative explanation for the drop in obesity with the defender assumption that would logically neutralize it.
- The city simultaneously launched a massive, free public gym program.The introduction of the free public gym program did not significantly contribute to the decrease in the city's obesity rate.
- A severe economic recession made high-calorie fast food unaffordable for most residents.The economic recession did not cause a reduction in caloric intake sufficient to explain the drop in obesity.
- The demographic makeup of the city changed, with an influx of young, active residents.The recent shift in the city's demographic makeup did not independently cause the observed reduction in obesity.
- A popular new diet fad that strictly forbids all carbohydrates swept the city.The popularity of the new low-carbohydrate diet was not the primary driver of the population's weight loss.
Answer
Each alternate explanation is matched with the statement that explicitly denies it, thereby defending the original argument.
Each matching pair correctly links a specific competing cause (on the left) with the assumption that explicitly eliminates that exact cause (on the right). Defender assumptions are logically necessary for a causal argument to survive when a plausible alternative explanation exists. By negating the alternate cause, the argument's original causal claim is protected.
Step-by-Step Solution
Key Concept
Defender assumptions protect causal arguments by explicitly ruling out alternative explanations or competing causes.