PT9.S2.Q7 Waste management failing to decrease the amount of plastic

AspiringAttorney_

I don't understand how D weakens the argument .Can someone please explain?

emmorens

This one is tricky but as I was reading it I immediately picked up on the % vs absolute number flaw. This is my rationale:

What we know from the stimulus:
1) Waste companies report that plastic makes up an ever-increasing percentage of the waste they handle.
2) Therefore the author concludes that it must be the case that attempts to decrease the amount of plastic people throw away are failing.

My immediate red flags:
While we know that the percentage of plastic has in fact gone up, we still don't have a clear picture about how much of the 'pie' it takes up compared to other waste items. I like to picture a pie chart in my head when dealing with percentages as they tend to get me confused.

Let's put this into context by giving the abstract percentages some absolute value:

Say in 2020 the total amount of garbage that the waste company dealt with was made up of the following:

• 100 plastic containers (50%)
• 100 pieces of paper/glass/metal (50%)

---

200 articles of waste total making up 100% of the pie

Now let's say in 2021 people stopped disposing paper, glass and metal entirely AND the amount of plastic they dispose actually also decreased.

• 50 plastic containers (100%)
• 0 pieces of paper/glass/metal (0%)

---

100 articles of waste total (100%)

This case draws a scenario where we are actually able to dispose of less plastic, while it's percentage increases!

This is because there were no other items to offset/balance the percentage (since we stoped disposing of paper/glass/metal entirely) - the percentage of plastic necessarily had to increase to account for the piece in the pie that paper/glass/metal used to occupy.

That's what AC D picks up on:
"An increasing proportion of the paper, glass, and metal cans that waste management companies used to handle is now being recycled"

A key distinction you have to make here is that these other types of waste are now being recycled rather than thrown in the garbage.

This weakens the authors argument that: 'attempts to decrease the amount of plastic that people throw away are failing'

Because how can we conclude that people aren't actually throwing out less plastic when we don't know anything about the absolute values? Maybe (like in the example above) other percentages just went down and that explains the increase in percentage for plastic. Which is precisely AC D.

I hope this was helpful & someone correct me if I made any errors!

leoxnardx

I eliminated D very quickly under time. What does paper, metal, glass have to do with the argument? Saw these three and clicked the x right away and didn't even read and chose B.

D weakens it because what we know from the passage is that the proportion of plastic that is recycled by the plant has been increasing. PROPORTION. Does that mean that the total quantity of the plastic they recycle has been constantly increasing? Maybe yes and maybe no. The author seems very convinced that the proportion being shooting up can be readily interpreted as the absolute quantity of the plastic going up.

That interpretation is the flaw in this argument. We simply cannot say that just because the proportion something takes up has become larger, it's quantity has become larger. Say you have 10 cats. 7 of them are yellow and 3 of them are black. The black cats take up 30% of your cat possession. Now you got into law school and realize "hmm maybe i have too many cats and I like the black ones more," and you decided to give 5 of your yellow cats to your parents. Now you have 5 cats, but the proportion of your black cats shoot right up to 60%. That doesn't mean that you acquired more black cats.

At this point the problem of the argument is clear. The proportion of plastic waste going up does not translate into an corresponding increase in its absolute quantity. That is exactly what D points out. The other things that the plant recycles have been decreasing. Just like you with your cat collection, the plant gives up on some other part of its waste recycling collection, leading to an increase in the proportion of plastic being recycled in the plant. Does that mean that the amount of plastic that is being recycled hasn't gone up? No, but we know that we can weaken the argument in this way so that it is not as likely that the plastic recycling encouragement has been failing.

AC B can be true and doesn't hurt the argument. It can totally be true that a lot of the plastics they process at the plant cannot be recycled, but that is not at all discussed in the argument. We only care about how much plastic people dispose, not how much RECYCLABLE plastic people dispose. Even the plastic treatment plant is not mentioned to be a plastic RECYCLING plant. So we don't need to care about whether the plastic are recyclable or not. This is the kind of worldly inference we make in our head, the kind that LSAT prohibits.