This is a Flaw/Descriptive Weakening question.
The stimulus says that if the proposed air pollution measures were to be implemented, ozone levels in the city's air would be one fifth lower, i.e., 20% lower, than current levels. Since the ozone in our air is currently responsible for $5 billion in health costs (premise), we would spend about a billion dollars less on these ozone-related health costs should the proposal be adopted (conclusion).
We always have two options when approaching Flaw questions. Either we identify the flaw in advance and go hunting for it in the answer choices, or use process of elimination. If you think this argument makes sense, keep an open mind as you go through the answer choices because the correct answer will point out something that you had not considered.
Answer Choice (A) says the argument fails to consider the possibility that other types of pollution not involving ozone might rise, perhaps even producing an overall increase in health costs. Sure, maybe particulate matter pollution or carbon dioxide pollution will rise. But the argument is completely contained to ozone and does not contemplate non-ozone-related health costs. So to criticize it for failure to do that is not a criticism of the logic of the argument.
(A) might be a fair criticism if we were having a discussion about health costs in general. But when we evaluate arguments in Weakening or Flaw/Descriptive Weakening, we have to limit that evaluation to the actual premise and conclusion presented, all of which are limited to ozone here. If (A) flies, then I can also say that the biggest contributor to health costs is heart diseases, not ozone, so we should talk about heart diseases if we really want to reduce health costs.
Correct Answer Choice (B) says the argument presumes, without providing evidence, that ozone-related health costs in the city vary roughly in proportion to ozone levels. This means if you reduce ozone levels by 20%, health costs would also go down by 20%. At a minimum, you should recognize that that is an accurate description of the assumption made. The argument is in fact presuming this, so (B) passes step one of the two-step test.
Now ask yourself if it is in fact reasonable to assume this. It turns out it is not. Ozone levels could generate health costs once the level of ozone passes a certain threshold. So it could be that ozone pollution is negligible until after a critical mass of the pollution has been accumulated, after which it becomes very damaging. If that were the case, then the 20% reduction might bring ozone levels under the threshold, which would result in health benefits of $5 billion. The opposite could also be true. Ozone levels could still be above the threshold even after the reduction, in which case we might not reduce health costs at all.
I am not saying this is how ozone levels actually work, but the point is that because we do not know how they work, we cannot make the naive assumption that the relationship between ozone levels and health care costs is proportional. There are so many other non-proportional relationships. And finally, in reality, the economic concept of diminishing marginal returns cuts against the assumption of proportionality.
Answer Choice (C) says the argument provides no explicit reason for believing that the proposed air pollution measures will in fact be adopted. Like (B), (C) is descriptively accurate. We do not know if the measures will be adopted or not. However, this is not the flaw. The premise says, “if the proposed air pollution measures were to be implemented,” so it is contemplating a hypothetical world. If we adopt it, what would happen?
Answer Choice (D) says the argument attempts to support the conclusion by making an appeal to emotions. The conclusion is supported by an appeal to math, not emotions. We think we would reduce health costs by 20% because the ozone levels will go down by 20%. An argument that did appeal to emotions would say something like “we should adopt the new ozone control measures because Timmy lost his mother to ozone pollution.”
Answer Choice (E) says the argument discusses air pollution to draw attention away from more significant sources of health-related costs. An argument actually guilty of this vulnerability would establish that a more significant source of health cost was, for example, heart disease. And the author would say, have you guys considered air pollution? There is ozone, nitrogen, volatile organic compounds, etc. That is trying to draw attention away from heart disease, which does not happen here.
This is a Necessary Assumption question.
The stimulus says recently discovered clay tablets from southern Egypt date to between 3,300 and 3,200 B.C. Though most of the tablets translated thus far are tax records, one of them appears to contain literary writing. All of this is premise supporting the conclusion.
And the conclusion is that these tablets challenge the widely held belief among historians that the Sumerian civilization in Mesopotamia was the first to create literature. So we used to think that the Sumerians were the first, and somehow these tablets challenge that, meaning the Egyptians predate the Sumerians. If you already spotted this assumption, you can just go hunting for the correct answer. But we’ll use process of elimination here.
Answer Choice (A) says most of the recently discovered tablets that have not yet been translated contain literary writing. So in the entire set of recently discovered tablets, there is a subset that has not yet been translated. And in that subset, most contain literary writing.
We do not need this to be true. We already have one of the tablets that contain literary writing and that is enough. Sure, having more would strengthen this argument, but we are just trying to find the necessary assumption. Running the negation test also helps. Say not most but rather just a few of the tablets contain literary writing. The argument does not fall apart.
Answer Choice (B) says every civilization that has kept tax records has also kept other written records. This is also not necessary. We are only talking about two civilizations, the Egyptian and the Sumerian. Why do we care if some other civilization like the Aztecs kept other written records? What does that have to do with this argument? Egypt still predates, or does not predate, the Sumerians in creating literature.
Correct Answer Choice (C) says historians generally believe that Sumerians did not create literature earlier than 3,300 B.C. This has to be true. Imagine if historians generally believed that the Sumerians did create literature earlier than 3,300 B.C., say 4,000 B.C. That is 6,000 years ago. And now we have this Egyptian tablet from 3,300 B.C., only 5,300 years old at best. How is this supposed to challenge the belief that Sumerians were the first to create literature? The Sumerians still predate the Egyptians by 700 years. That is why (C) is absolutely necessary.
Note that this question could have been way harder. Imagine if one of the other answer choices said historians generally believe that Sumerians first created literature between 2,800 B.C. and 2,700 B.C. This would be a super attractive answer choice. However, while this would certainly help the argument by definitively showing that Egyptian literature is older by about 600 years, it is not necessary. And you can see this is not necessary by changing the dates a bit, say 2,500 and 2,400 B.C. That would also help the argument. So it is not necessary that historians have to believe in the 2,800 to 2,700 B.C. date range.
Answer Choice (D) says some historians are skeptical about the authenticity of recently discovered tablets. This is not necessary. If anything, the skepticism only hurts the credibility of the argument. Necessary Assumption is part of the superset that we call Strengthening.
Answer Choice (E) says the Sumerian civilization arose sometime between 3,300 B.C. and 3,200 B.C. This is also not necessary. What if it instead arose between 2,800 and 2,700 B.C.? Falsifying, or negating, (E) does not ruin the argument. If anything, this version of falsification actually helps the argument. Egypt would clearly predate the Sumerians in this scenario because the Egyptian clay tablet would be dated to be 500 years older than the Sumerian civilization itself.
A
Some scientists have found evidence that the waters off the Pacific coast of North America have grown significantly warmer over the past 15 years.
B
The warming of the waters off the Pacific coast of North America is not a symptom of a more general, global warming caused by human-generated air pollution.
C
The conclusion that the warming of the waters off the Pacific coast of North America is a symptom of a more general, global warming caused by human-generated air pollution is far from justified.
D
The warming of the waters off the Pacific coast of North America may be the result of a natural cycle of ocean temperature changes.
E
If the warming of the waters off the Pacific coast of North America is due to a natural cycle of ocean temperature changes, then it is not a symptom of a more general, global warming caused by human-generated air pollution.
Kendall: But what artifacts a people make is determined largely by the materials available to them.
A
the distinction that Robin makes between two kinds of cultures is illicit
B
it is reasonable to assume that a culture whose artifacts were not durable was nomadic
C
any evidence other than the intended durability of a culture’s artifacts can establish conclusively which of the two kinds of cultures a particular culture was
D
the distinction that Robin makes between the different kinds of cultures is as important as many archaeologists have thought
E
studying a culture’s artifacts can reveal a great deal about the culture
A
The volume of freight shipped by rail can be expected to increase.
B
Increasing reliance on automation means that fewer railroad workers are needed.
C
No reduction in operating costs is predicted for the trucking industry.
D
Operating costs for railroads have been reduced as a result of increased reliance on automation.
E
The chief competitor of railway shipping is shipping by truck.
A
Boiled cow’s milk makes less vitamin C available to infants than does the same amount of mother’s milk.
B
Infants who consume cow’s milk that has not been boiled frequently contract potentially fatal gastrointestinal infections.
C
Mother’s milk can cause gastrointestinal infections in infants.
D
When doctors advised that cow’s milk fed to infants should be boiled, they did not know that scurvy was caused by vitamin C deficiency.
E
When doctors advised that cow’s milk fed to infants should be boiled, most mothers did not breast-feed their infants.
A
Fire departments tend to receive less funding during periods of severe drought than during periods of normal rainfall.
B
Areas subject to grass and brush fires tend to be less densely populated than areas where there are few such fires.
C
Unusually large, hard-to-control grass and brush fires typically occur only when there is a large amount of vegetation for them to consume.
D
Grass and brush fires that are not caused by human negligence or arson tend to be started by lightning.
E
When vegetation is destroyed in a grass or brush fire, it tends to be replaced naturally by vegetation that is equally if not more flammable.
This is a Weakening question.
In Weakening questions, we take away the support that the premise provides to the conclusion. We usually do this by identifying an assumption in the argument and stating the opposite of that assumption.
The stimulus says that the government’s tax collection agency (i.e., IRS) has not followed through on its plan, announced a year ago, to crack down on violations of corporate income tax law. This is the conclusion. And the premise for this conclusion is that audits are the primary tool for detecting such violations, and over the past year, not a single audit of corporate income tax returns has been completed.
So far, it sounds like the IRS is doing a pretty bad job following through on its plan. But wait, we’re not supposed to like this argument. We’re supposed to identify where this argument is weak.
If you feel this way at the end of a stimulus, that’s okay. Just remind yourself to be skeptical and then look at the answer choices. Perhaps one of them will clue you in on where the argument is weak.
Answer Choice (A) says the plan to crack down on violations of corporate income tax law is part of a broader campaign against corporate misconduct. So who cares if some other agencies like the SEC or the FTC also announced their plans? We are discussing whether the IRS followed through on its plan, so (A) is entirely irrelevant.
Answer Choice (B) says the number of personal income tax returns audited over the past year is greater than in previous years. There is a big difference between corporate income tax and personal income tax, which makes (B) irrelevant. While (B) might become more relevant if you misread personal as corporate, (B) is useless as it currently stands.
Answer Choice (C) says most audits of corporate income tax returns do not reveal any significant violations. All (C) tells us is that, of the set of all audits of corporate income tax returns, only a minority revealed significant violations. How does this information even fit into the stimulus? It still stands that zero audits were completed last year.
Answer Choice (D) says it generally takes longer than one year to complete an audit of a corporate income tax return. This reveals the naive assumption the argument made. For example, if it only takes three months to complete an audit and the IRS had completed zero audits, we can say it did not follow through on its plan. However, if it takes more than a year to complete an audit, the IRS could have followed through on its plan by having initiated many audits in the past year even though none were completed.
While the information in (D) does not challenge the truth of the premise, it changes its significance. The fact that the IRS had completed zero audits now has no power to show that it did not follow through on its plan. This a quintessential correct answer choice in a Weakening question. (D) does not challenge the truth of the premise or the conclusion, but it does weaken the support that the premise gives to the conclusion.
Answer Choice (E) says that over the last five years, fewer audits of corporate income tax returns have been completed than in the preceding five years. (E) might relate to the argument by revealing the reason why the IRS said they were going to crack down on tax violations. They might have realized that they are auditing less than they used to and decided to pick up the pace. But even so, this does not weaken the argument.
This is a Flaw/Descriptive Weakening question.
The stimulus says that making some types of products from recycled materials is probably as damaging to the environment as it would be to make those products from entirely nonrecycled material. This is the conclusion. If we use soda cans as an example, making soda cans from recycled aluminum is just as damaging to the environment as making them from new aluminum.
Why is this so? The premise is that the recycling process for those products requires as much energy as producing them from raw materials, and almost all energy production damages the environment. Okay, so producing a recycled aluminum can and a new aluminum can are equally damaging to the environment in terms of energy production.
But does that mean they are equally damaging to the environment, period? What about the actual materials used? Surely we cannot assume that energy production is the only factor that determines environmental damage. The fact that a recycled can’s aluminum came from other cans and not aluminum mines has to count for something.
The reasoning here is cost-benefit analysis, and the author failed to consider other costs and benefits. The argument accounted for energy production as a component of environmental damage but forgot to account for other components. We’re not looking at causal reasoning.
Since we spotted the flaw, let’s turn to the answer choices.
Answer Choice (B) says that the argument treats an effect of energy-related damage as if it were instead the cause of such damage. What is the effect of energy-related damage? Maybe we will see 80-degree weather in New York on Christmas, but why is this relevant? The argument is not even close to a causal one and (B) does not describe the argument’s flaw.
Answer Choice (E) says that the argument presumes that simply because one phenomenon follows another, the earlier must be a cause of the later. Both (B) and (E) describe cookie-cutter flaws related to causation, and if such flaws were actually present in the argument, they would be the right answer choice. But (E) has nothing to do with this argument.
Answer Choice (A) says that the argument uses the word “environment” in one sense in the premise and in a different sense in the conclusion. (A) describes another cookie-cutter flaw that could be correct in other questions, but not in this one. It accuses the argument of having shifted the meaning of a key term or phrase, but it is clear that the premise and the conclusion are referring to the same concept of environment.
Answer Choice (C) says that the argument fails to consider that the particular types of recycled products that it cites may not be representative of recycled products in general. However, the columnist explicitly said making some types of products from recycled material is probably as damaging, not that recycling is just as damaging in general as making products from new materials. And surely the columnist never cited any particular types of products. While I used soda cans to illustrate the argument, the columnist’s argument was nonspecific.
Answer Choice (D) says that the argument fails to consider that making products from recycled materials may have environmental benefits unrelated to energy consumption. This successfully picks up on the accounting error we spotted earlier. This is a benefit of recycling that the argument failed to account for.
This is an Argument Part question.
We have to identify the role of the statement that “people who are constantly subjected to fire drills eventually come to ignore the fire alarm.”
The stimulus says that we are constantly bombarded by warnings, based on initial studies' tentative conclusions, about this or that food having adverse health effects. For example, we are warned that fat is good one day then bad the next, and these warnings are only based on initial studies' tentative conclusions.
Then it says that if the medical establishment wants people to pay attention to health warnings, it should announce only conclusive results, the kind that can come only from definitive studies. This is the conclusion. And why should we believe this? After all (this is a premise indicator), people who are constantly subjected to fire drills eventually come to ignore the fire alarm. This is the statement whose role we have to identify, and we have just identified that it is a premise.
But this is a premise that supports the conclusion via reasoning by analogy. Author says constantly bombarding people with health warnings is just like constantly subjecting people to fire drills. Constant fire drills only train people to ignore the fire alarm, and similarly, people are going to stop paying attention to health warnings if they are constantly bombarded by them.
Answer Choice (A) says that the statement is presented as an example of the sort of warning referred to in the argument's overall conclusion. It is not. Examples of such warnings would be warnings that are based on definitive studies such as three decades of nutritional studies that have conclusively shown that sugar above a certain amount is bad.
There is a big difference between examples and analogies. Examples are particular instances of generalities. Analogies come from a different set of generalities but share certain features we identify as similar.
Answer Choice (B) says that the statement plays no logical role but instead serves to impugn the motives of the medical establishment. The statement does play a logical role, and it does not impugn the motives of the medical establishment. Such a claim might be something like “the medical establishment receives a ton of funding from food companies that skew their incentives to do objective science.”
Answer Choice (C) says that the statement is an analogy offered in support of the argument's overall conclusion. Perfect.
Answer Choice (D) says that the statement is an analogy that forms part of a scientific objection to the argument's overall conclusion. While the analogy is an objection to something, it is definitely not an objection to the conclusion. Within the conclusion, there is an objection to bombarding people with health warnings. And the statement supports this objection, which means it is supporting the conclusion, not objecting to it.
Answer Choice (E) says that the statement is an analogy offered to clarify the distinction that the physician makes between an initial study and a definitive study. While the physician does make this distinction, a clarification of this distinction is never provided.