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Chart

The above chart was recently published on Reddit. ( Source: r/dataisbeautiful )

The author of the reddit thread cites the following data sources:

I'm interested in verification if the overall picture is accurate, hugely exaggerated, or even underestimating the real trend.

Clarification edit:

I'm not doubtful of the correctness of the data, as the data source could be considered a generally trustworthy one.

However, what I don't know is how well this data reflects the reality of students today. How "complete" is this set of data, and are the books making up the majority of that data really the same ones used as textbooks in universities and schools? In short: Are these really representative values? I also could not find the information which books exactly make up the index.

In short, my skepticisms is aimed at the interpretation of the data more than the actual values used to produce it. In particular so, as the apparent 'take-home' message of the chart is very, very strong.

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    That's a very well-sourced graph. Do you have any particular reason to doubt the numbers of the U.S. Bureau of Labor Statistics?
    – DevSolar
    Mar 7, 2019 at 9:52
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    My main issue with the graph is that they use 100 as a baseline but don't even bother to mark it with a grid line.
    – pipe
    Mar 7, 2019 at 10:28
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    @DevSolar I don't have issues with the correctness of the data, but I can't find the information how representative it is for "textbooks". i.e. I belive that the books in the data show this increase, but how "complete" is this set of data? And does it f.e. relate to "textbooks really used in educational courses" overall. My skepticism regards cherry-picking data and misrepresentation. And: I don't say it's wrong, I just want a double-check on this.
    – BmyGuest
    Mar 7, 2019 at 10:57
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    @BmyGuest DevSolar's question about the data is a good one, and you have a good answer for him. I suggest you edit your response into the question, because it really makes clear what a good answer will do. Mar 7, 2019 at 15:51
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    @pipe it's also set with the baseline at about 85, so the graph makes it look like textbooks are 7x more expensive instead of only 2x. Even though it is correctly interpreted in the question here, the graph itself clearly is intended to exaggerate the change.
    – Hellion
    Mar 7, 2019 at 16:15

1 Answer 1

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I would say that there are similar figures showing a similar trend (source) with the statistics directly available online at a .gov website.

enter image description here

The President of the University of Missouri System has even directly acknowledged this trend.

In real terms, college textbook prices have increased by 90% while recreational book prices have fallen by more than 35%...For these reasons, the four UM System campuses announced their collective commitment to adopt open educational resources.

It is also referenced to by CSU Chico.

Also note that the percentage values are relative to the Consumer Price Index (CPI) in 2004 rather than 1998, as in the Figure posted in this answer. Keep in mind that the cost of all items has increased in the present time relative to an earlier time (e.g. 2004), so dramatic increases may not be so dramatic on a relative scale (compared to childcare, housing, etc.).

Additional questions posted in the comments:

What counts as a "college textbook?"

From here:

College textbooks... includes any book, which, according to the outlet, has been designated by the college, department, or professor, as a required text for a course offered by the college during the academic period.

Is any weighting done or would a single super-expensive book only being used in a single college of the US contribute equally to it as a massively-used book would?

The only information I can find regarding weighting is here:

Recorded price changes are weighted by the importance of the item in the spending patterns of the appropriate population group.

I would assume that textbooks which are frequently purchased by college students are more important in the "appropriate population group" than other less frequently purchased textbooks. So, yes, weighting is done and a single rarely-purchased super-expensive book would be given a lower weight than commonly-purchased cheaper books.

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  • Thanks. "College Textbooks" is already much more defined than "educational books". Do you have data on what makes it into this data-set and what doesn't? Is it the sum of books intended for college-use (by the author/publisher) or is it the sum of books used in colleges? Is any weighening done or would a single super-expensive book only being used in a single college of the US contribute equally to it as a massively-used book would?
    – BmyGuest
    Mar 7, 2019 at 19:23
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    @BmyGuest I will edit the answer to answer your additional questions. Mar 8, 2019 at 7:01
  • Thanks Barry. I think this is as detailed as I could hope to find.
    – BmyGuest
    Mar 8, 2019 at 7:10
  • You are welcome! Glad to help! Mar 8, 2019 at 7:11

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