Logical ReasoningDifficulty: Hard

PT16 S2 Q14 Explanation

In 1980, Country A had a per capita

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsNecessary Assumption

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Stimulus

In 1980, Country A had a per capita gross domestic product (GDP) that was $5,000 higher than that of the European Economic Community. By 1990, the difference, when adjusted for inflation, had increased to $6,000.Since a rising per capita GDP indicates a rising average standard Country A must have risen between 1980 and 1990.

What this question is testing

Necessary Assumption

Your task

Find the assumption the argument requires in order for its conclusion to hold.

Common trap

Answers that would help the argument but aren't strictly required (sufficient, not necessary).

Winning move

Negate each choice — the right one breaks the argument when negated.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
14.

Which one of the following is an assumption on which the

Answer choices

  1. Too Strong: Same21% picked this

    Between 1980 and 1990, Country A and the European Economic Community experienced the same percentage

    "Same" is like "Identical". The author doesn't need to believe this incredibly improbable idea that Country A and the EEC increased by exactly the same increase in population.

  2. Opposite: standard of living fell6% picked this

    Between 1980 and 1990, the average standard of living in the European

    The author is failing to consider that the EEC's per capita GDP may have gone down. The author is assuming that EEC's per capita GDP is the same or higher than before. So it wouldn't make sense, given that, for the author to think that standard of living is falling, while GDP is the same or higher.

  3. Irrelevant Comparison5% picked this

    Some member countries of the European Economic Community had, during the 1980s, a higher average standard of

    There's no reason the author needs to believe that at least one European country had higher standard of living that Country A. If we negate this, we're saying, "Country A's standard of living was as high or higher than that of all European countries". Does that hurt the argument? Not really, it sounds more like it goes with the conclusion.

  4. Correct60% picked this

    The per capita GDP of the European Economic Community was not lower by more than $1,000 in 1990 than

    Why this is right

    Whenever we're doing Necessary Assumption and we see an answer choice ruling-out an idea with "not / no", we should slow up and negate it. Tons of correct answers (we call them Defender answers) look like this. If we say that per capita GDP of Europe was more than $1k lower in 1990, that means that the gap between Country A and Europe is widening because Europe is slipping, not because Country A is surging. Thus we have no reason to think that Country A's GDP is actually rising. The author needs us to believe that A's GDP is rising in order to get to her conclusion about standard of living. So we can see that negating this answer badly weakens the argument by offering an alternate explanation for the "$5k higher to $6k higher" curious fact.

    Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.

  5. Too Strong: no member7% picked this

    In 1990, no member country of the European Economic Community had a per capita GDP higher than

    This is very harsh. No one was higher than A? Country A had to have the highest GDP? The author wasn't assuming anything that strong. But people may find this tempting since we're told that Country A's GDP is $5-6k higher than Europe's. However, that latter number is an average, not a total. "Per capita" means per person. Say that the entire European community was just Germany and Switzerland. Germany might have a $50k / person GDP while Switzerland has $10k / person GDP. That would mean that this European community has a per capita GDP somewhere around $30k. For Country A to be higher than the per capita GDP of the European Community, we're saying that if you added up total value produced and divided by number of citizens, the number would be $5-6k higher for Country A than for Europe. But the European countries are all being averaged together for that latter number. It's highly possible some outlier nations have way higher GDP than the European average (and thus higher than Country A).

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