Mysterious ancient tracks cut into limestone have recently been found on the island of Malta. The tracks wander, sometimes disappearing under modern structures. Their origin and purpose are unknown, but evidence indicates that they could have connected settlements or water sources. One archaeologist hypothesizes, based on the tracks’ physical appearance and surroundings, that they were made in about 1000 B.C. by animal-drawn carts.

Summarize Argument: Phenomenon-Hypothesis
The archaeologist hypothesizes that the mysterious tracks were made by animal-drawn carts in roughly 1000 B.C. This is based on the tracks’ appearance and surroundings.

Notable Assumptions
The archaeologist assumes that the tracks’ origin and date can be deduced by their physical appearance and surroundings.

A
Areas near the tracks have yielded relatively large amounts of fossilized animal excrement dating from approximately 1000 B.C.
Animals were clearly in the area of the tracks around 1000 B.C. This lends support to both the notion that animal-drawn carts made these tracks, and that these tracks were made in 1000 B.C.
B
Some of the tracks connect areas that are sources of fresh water on Malta today.
We don’t care what the tracks connect. We care how they were created in the first place.
C
Some terrain on the island of Malta is more easily traversed on foot than are certain other types of terrain there.
We have no idea if that terrain is the terrain around the tracks.
D
Historically, inhabitants of the island of Malta have not been innovative users of transportation technology.
We have no idea if animal-drawn carts constitute “innovation.” Besides, the Maltese could’ve received this technology from elsewhere.
E
Around 1000 B.C., some settlements were abandoned in parts of Malta.
We care about the tracks. We don’t care what happened to settlements.

7 comments

Among small- to medium-sized marine mammals such as seals and dolphins, the longer an animal can stay submerged during a dive, the greater the depth the animal can reach. Dolphins can dive to greater depths than northern fur seals can, and elephant seals can stay submerged longer than Weddell seals can.

Summary
Among small-to-medium-sized marine mammals, the longer an animal can stay submerged during a dive, the greater the depth the animal can reach. Dolphins can dive to greater depths than northern fur seals can. Elephant seals can stay submerged longer than Weddell seals can.

Notable Valid Inferences
For MBT-Except questions, the wrong answers are all Could Be True. The one right answer Must Be False.
Dolphins can dive to greater depths than Weddell seals, but not as deep as Elephant seals can.
Northern fur seals can dive to greater depths than Weddell seals, but not as deep as Elephant seals can.

A
Dolphins can dive to greater depths than Weddell seals can, but not to depths as great as elephant seals can.
Could be true. It is possible for dolphins to dive to a depth greater than Weddell seals but not as deep as elephant seals.
B
Weddell seals can stay submerged longer than northern fur seals can, but dolphins can dive to greater depths than Weddell seals can.
Could be true. It is possible for Weddell seals to dive to a depth greater than northern fur seals but not as deep as dolphins.
C
Weddell seals can dive to greater depths than dolphins can and can stay submerged longer than northern fur seals can.
Must be true. The stimulus tells us that dolphins can dive to greater depths than northern fur seals. If Weddell seals dive deeper than dolphins, then they must also dive deeper than northern fur seals.
D
Northern fur seals can stay submerged longer than elephant seals can, but Weddell seals can dive to greater depths than dolphins can.
Must be false. It is impossible for Weddell seals to dive deeper than dolphins if northern fur seals dive deeper than elephant seals.
E
Northern fur seals can stay submerged longer than Weddell seals can, but elephant seals can dive to greater depths than northern fur seals can.
Could be true. It is possible for northern fur seals to dive to a depth greater than Weddell seals but not as deep as elephant seals.

31 comments

The stimulus tells us that tariffs help a small group of people (let's say 10 people) but hurts a large group of people (let's say 100 people). You take a poll of all the people (110) and no surprise, most are opposed to the tariffs (say all 100 are opposed).

Great. That's it. 10 people are for the tariffs. 100 are against.

Now imagine you're the politician and you know these facts. What platform are you going to run? An anti-tariff platform? Maybe. It's not entirely unreasonable. But you should identify the assumption you'd be making if you were to run anti-tariff. Namely, that the tariff issue is important to those 100 people.

Obviously, you want to harness votes and avoid driving votes away. If you assume the world is such that tariffs matter equally to everyone, then an anti-tariff platform would harness 100 votes and drive away 10 votes. You come out +90 votes, good.

Negating (A) severely challenges the assumption. It opens up the possibility that the actual world is one in which the pro-tariff 10 people care way more about the tariff than the anti-tariff 100 people. If that were the case, then an anti-tariff platform would for sure lose you 10 votes without a guarantee of adding any additional votes.

We know this intuitively in the real world. People care about many many things. But not all of those things translate into political action through voting. In other words, the set of things that people vote on is a small sub-set of the things that people care about.

The phenomenon that (A) hints at is actually very well documented in economics and politics. The issue is one of concentrated benefits versus diffuse costs. Think of it like this. There's a set of laws that allow you to take a penny from everyone in the country each year. You're net positive roughly $3 million each year. Everyone is hurt one penny each year. Who cares about that law more? Of course you do. You care intensely that that law remain in place and you will take political action to ensure that it does. This would at minimum include voting on that basis but more likely even include lobbying. Me? I sort of care a little maybe that that law gets repealed. Certainly I don't care from a selfish economics perspective, after all I only stand to gain 1 penny. I have to find motivation to care from a justice or fairness principle and that's harder to muster. I very likely will not take any political action on this issue.

In most states, lobbyists ensure that legislation force the retail distribution of cars through dealerships, even if direct distribution from the manufacturer to the consumer is more economically efficient. But the benefits of this regime are concentrated to the dealerships (it's their entire livelihoods!) while the costs are diffused to everyone else (everyone pays a little more for their cars and manufacturers earn a little less). The vocal minority with a lot to gain will organize politically while the indifferent majority with little to lose individually will not. The end result is a net loss for society.

The presence of concentrated benefits versus diffuse costs is a bug in our political system, not a feature.


1 comment

The stimulus tells us that tariffs help a small group of people (let's say 10 people) but hurts a large group of people (let's say 100 people). You take a poll of all the people (110) and no surprise, most are opposed to the tariffs (say all 100 are opposed).

Great. That's it. 10 people are for the tariffs. 100 are against.

Now imagine you're the politician and you know these facts. What platform are you going to run? An anti-tariff platform? Maybe. It's not entirely unreasonable. But you should identify the assumption you'd be making if you were to run anti-tariff. Namely, that the tariff issue is important to those 100 people.

Obviously, you want to harness votes and avoid driving votes away. If you assume the world is such that tariffs matter equally to everyone, then an anti-tariff platform would harness 100 votes and drive away 10 votes. You come out +90 votes, good.

Negating (A) severely challenges the assumption. It opens up the possibility that the actual world is one in which the pro-tariff 10 people care way more about the tariff than the anti-tariff 100 people. If that were the case, then an anti-tariff platform would for sure lose you 10 votes without a guarantee of adding any additional votes.

We know this intuitively in the real world. People care about many many things. But not all of those things translate into political action through voting. In other words, the set of things that people vote on is a small sub-set of the things that people care about.

The phenomenon that (A) hints at is actually very well documented in economics and politics. The issue is one of concentrated benefits versus diffuse costs. Think of it like this. There's a set of laws that allow you to take a penny from everyone in the country each year. You're net positive roughly $3 million each year. Everyone is hurt one penny each year. Who cares about that law more? Of course you do. You care intensely that that law remain in place and you will take political action to ensure that it does. This would at minimum include voting on that basis but more likely even include lobbying. Me? I sort of care a little maybe that that law gets repealed. Certainly I don't care from a selfish economics perspective, after all I only stand to gain 1 penny. I have to find motivation to care from a justice or fairness principle and that's harder to muster. I very likely will not take any political action on this issue.

In most states, lobbyists ensure that legislation force the retail distribution of cars through dealerships, even if direct distribution from the manufacturer to the consumer is more economically efficient. But the benefits of this regime are concentrated to the dealerships (it's their entire livelihoods!) while the costs are diffused to everyone else (everyone pays a little more for their cars and manufacturers earn a little less). The vocal minority with a lot to gain will organize politically while the indifferent majority with little to lose individually will not. The end result is a net loss for society.

The presence of concentrated benefits versus diffuse costs is a bug in our political system, not a feature.


47 comments

Most of the mines that Moradco operates in the province of Velyena have never violated environmental regulations. Every one of the gold mines that Moradco operates throughout the world has at some time or another violated environmental regulations.

Summary
Most mines that Moradco operates in the province of Velyena have never violated environmental regulations. Every gold mine Moradco operates has at some time violated environmental regulations.

Notable Valid Inferences
Most of the mines Moradco operates in Velyena are not gold mines.

A
Moradco operates more mines in Velyena than any other company operates there.
Could be false. We don’t have any information in the stimulus about the total number of mines to make this comparison. Our conditions are restricted to the proportion of mines that have or have not violated environmental regulations.
B
The total number of gold mines that Moradco operates is larger than the total number of mines it operates in Velyena.
Could be false. We don’t have any information in the stimulus about the total number of mines to make this comparison. Our conditions are restricted to the proportion of mines that have or have not violated environmental regulations.
C
Most of the gold mines that Moradco operates are not located in Velyena.
Could be false. We don’t have any information in the stimulus about the total number of mines Moradco operates to make this statement. We cannot assume that just because most mines in Velyena have not violated environmental regulations that most mines are not located there.
D
Most of the mines that Moradco operates in Velyena are not gold mines.
Must be true. As shown below, we can take the contrapositive of the last statement in the stimulus which tells us that if a mine has never violated environmental regulations, then that mine is not a gold mine.
E
Most of the mines that Moradco operates throughout the world are not gold mines.
Could be false. We don’t have any information in the stimulus about the number of mines Moradco operates outside of the province of Velyena. It is possible that most of Moradco’s mines are in Velyena.

9 comments

Everyone should have access to more than one newspaper, for there are at least two sides to every story. Since all sides of an important story should be covered, and no newspaper adequately covers all sides of every one of its stories, some important stories would not be adequately covered if there were only one newspaper.

Summarize Argument
The author concludes that everyone should have access to more than one newspaper. This is based on a subsidiary conclusion that, if there were only one newspaper, some important stories wouldn’t be covered. The author supports this subsidiary conclusion by noting that there are at least two sides to every story, and no single newspaper adequately covers all sides of every story.

Identify and Describe Flaw
The author overlooks the possibility that even if no newspaper adequately covers all sides of every story, they might be able to cover all sides of every important story. The statement that newspapers can’t adequately cover “all sides of every story” means only that less than 100% of stories have all sides covered. But this doesn’t mean every single story will have inadequate coverage. Some stories can have all sides covered; those stories might be the important ones.

A
The argument confuses the inability to cover all sides of every story with the inability to cover all sides of any important story.
Premises establish only that newspapers can’t cover all sides of every story. (Some stories won’t be adequately covered.) The author thought this implies newspapers can’t cover all sides of any story. (Every story, including all important ones, will not be adequately covered.)
B
The argument overlooks the possibility that two newspapers could provide the same incomplete coverage of the same important stories.
This possibility doesn’t hurt the argument, because the author never concludes that having 2 newspapers is sufficient to see all sides of important stories. Having only 1 isn’t enough. But the author never said having 2 is enough.
C
A conclusion about what newspapers should do is inferred solely from statements about what newspapers in fact do.
The conclusion is not about what newspapers should do. It’s about what people (”everyone”) should have access to. Also, one of the premises asserts that all sides of an important story “should” be covered. So the premises are not just factual statements about what newspapers do.
D
The argument takes for granted that everyone has access to all newspapers.
The author doesn’t assume that everyone can access all newspapers. What people “should” be able to access is separate from what they in fact can access.
E
The argument is concerned only with important stories and not with all stories.
There’s nothing flawed about making an argument focused only on important stories. What matters is whether the premises prove the conclusion. The choice of what kind of story to focus on in the argument is not itself a flaw.

75 comments