Logical Reasoning

PT14 · S2 · Q10 The government of Penglai, an

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The government of Penglai, an isolated island, proposed eliminating outdoor advertising except for small signs of standard shape that identify places of business.

Merchants' Conclusion

The law that would eliminate outdoor advertising (other than small standardized signs) would reduce the overall volume of business in Penglai.

Merchants' Evidence

In every industry on Penglai, the businesses that used outdoor advertising had a larger market share than those that did not.

Evaluate

The evidence is a correlation: people who had Trait A had more Trait B than those who did not have Trait A.

So we know that outdoor advertising is correlated with larger market share.

Are the merchants assuming this is a causal connection, that outdoor advertising causes more market share?

Yes, they seem to be thinking that, because they are suggesting that the elimination of outdoor advertising will have a causal effect on business.

When an author assumes that a correlation between X and Y means that X causes Y, we respond with two automatic thoughts: 1. could it be reverse cause? could Y cause X? 2. could there be some third factor? could Z cause X and Y?

#1 seems plausible. Maybe the larger market share came first, and because those businesses were successful, they (and not the businesses are with the smaller market share) could actually afford outdoor advertising.

#2 is possible. Maybe the businesses most likely to use outdoor advertising have beautiful people that work there, and maybe having beautiful people work at a business causes it to be more successful and have a bigger market share. (This is a dumb story, but just an example)

Goal

Let's look for an answer calling out this Correlation to Causality move (that is one of the top 10 Famous Flaws).

Or look for an answer that would otherwise help us argue that .

10.

Which one of the following describes an error of reasoning in the merchants’ argument?

presupposing that there are no
Too Strong: no good reasons
Presupposing = takes for granted = assumes, like in Necessary Assumption. Did the merchants have to assume that there are zero good reasons to restrict outdoor advertising? Not at all. They could easily accept that there is at least one good reason to restrict outdoor advertising, while still lamenting that doing so would reduce the overall volume of business in Penglai.
4% picked this
Correct
assuming without giving justification that
Why this is right
This is also presenting a supposed Necessary Assumption. Do the merchants need to assume that outdoor advertising increases market share by some means other than by diverting trade from competing businesses? That's a mouthful. Let's see if negating this answer would weaken: Outdoor advertising only increases market share by diverting trade from competing businesses That does weaken, but it's not likely to 'click' for most people, unless they picked up on a weirdness to the argument (unrelated to the Famous correlation = causation flaw). Penglai, we are told, is an isolated island. Some people live there and probably don't leave much, since it's expensive to go back and forth to an isolated island. Some people may travel there for vacation. The merchants' conclusion is worried about the "overall volume of business" that gets done in Penglai. Maybe in 2020, $2 billion worth of transactions occurred. How would eliminating outdoor advertising change that? If you live on the island, you're still spending the same amount of your income on necessities and luxuries, whether businesses have an outdoor ad or not. If you're a tourist visiting, you're still spending the same amount of your vacation budget there. You showed up ready to blow $1000 during your week in Penglai. That's the volume of business you're creating. If there are outdoor ads for certain places, you might be more likely to spend your money at that restaurant rather than at some other restaurant that doesn't have an outdoor ad, but if we take away these outdoor ads, you're still going out to dinner at some restaurant. The idea is that outdoor ads are more likely to affect where you spend your money than they are to affect whether you spend your money. The merchants are acting like if there aren't outdoor ads, then people just won't take out their wallet as much. When we negate the assumption in this answer choice, we are objecting, "What are you talking about? Sure, outdoor ads can help a business gain bigger market share. But that's not be cause outdoor ads create sales that wouldn't otherwise exist. The same volume of money is going to be spent either way. Outdoor ads just funnel money more towards the advertised businesses than towards non-advertised businesses."
Skill tested: Flaw · how this choice captures the argument's function is the move to repeat next time.
54% picked this
ignoring the question of whether
Not an Objection
Yes, the author fails to address whether the survey of the island could really be objective. But is that really our complaint with the merchants' logic? That sounds more like we're just attacking the validity of their premise. Moreover, we have no reason to think that this survey might be subjective, biased, or skewed. The survey is collecting very objective, quantifiable data: - do you / don't you use outdoor ads - what is your market share
2% picked this
failing to establish whether the
Too Strong: precisely proportionate
Fails to establish = takes for granted = presumes = Necessary Assumption answers. Did the merchant need to assume that the market-share advantage by businesses that do outdoor advertising was precisely proportional to the amount of advertising? i.e. did they need to assume that if business X does 17% more outdoor advertising than business Y, then business X will have precisely 17% more market share? Of course not. That's a completely unrealistic expectation. The merchants just think that the outdoor ads have some causal impact on market share. They don't need to think that it's precisely 1:1.
40% picked this
disregarding the possibility that the
Not an Objection
When we see fails to consider / ignores the possibility, then we ask ourselves whether the idea that follows would be a Weakening objection. Can we hurt the merchants' argument by saying, "Yo -- the proposed restrictions are unconstitutional"? No. That has no effect on the claim that "the proposed restrictions will reduce overall volume of business". Whether or not something is constitutional is a totally separate issue from whether or not that something would have an effect on overall volume of business.
0% picked this

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