 Good morning, Hank, it's Tuesday, so textbooks are expensive. In fact, since I was born, average textbook prices have gone up by a factor of more than 8, far faster than inflation or housing prices or even medical care. Americans spent over $10 billion last year on textbooks, which is significantly more than we spent on all fiction, like every print book and e-book and audiobook of Harry Potter and The Great Gatsby and Good Night Moon and those thrillers your dad reads and, oh my god, we spend so much money on textbooks. And what makes all this a little weird is that while textbooks are much more expensive than they used to be, they are also, like, less important. When I was a kid, if I wanted to learn about, say, geometry, textbooks were basically the only way. But now there are lots of options. There's Mathagon, an extraordinarily intuitive series of online courses that has interactive elements to help you understand and confirm what you're learning. Or you can watch three blue-one-brown videos that help visualize complicated mathematical concepts. Or you can follow Khan Academy's series on geometry, and all these learning tools and many others are entirely free. Now in many cases, they are not as comprehensive as textbooks, but on the other hand, they are much more interactive and also able to adapt to different needs for different students. And just to reiterate, instead of costing $10 billion per year, much of which is paid by underfunded public school systems, they cost nothing. Okay, so every year, Bill and Melinda Gates release an annual letter, and this year's letter is about surprises they've learned, from the ways that data can be sexist to how slow innovation in toilet technology has harmed human health. And they also say that textbooks are becoming obsolete. If you're interested in this kind of stuff, you should read the entire letter, link in the doobly-doo below. But in it, Melinda points out that almost half of college students are over the age of 25, and more than half have a job. And she writes that these students often don't have the time or resources to effectively navigate an inefficient, inflexible learning environment. I am definitely not an expert in this, but anecdotally, I do hear that from a lot of students. Like, price of educational materials is one barrier to post-secondary education, but the way those materials work or don't work is another barrier. And then for middle school and high school students, I often hear that there is a huge divide between the way that students actually learn and the way that teachers often want to teach, and the textbooks and other educational materials they are required to use. Most textbook buying decisions are not made by students or teachers or even school administrators. They are made at the district or state level. Now, of course, this standardization does exist for a reason. It's an attempt to make sure that teachers are using comprehensive and reliable resources to teach kids what they need to know. Also, I think people in so-called edu-tech have spent way too much time trying to replace teachers, which just ain't gonna work, in my opinion. There is no way to replace the incredibly vital person-to-person work that teachers do. As Bill says in the letter, effective educational materials should seek to be a compliment to what teachers do, not a replacement. So are textbooks becoming obsolete? Maybe, but I worry that like other things in our economy that are growing more expensive, textbooks are somewhat impervious to the law of supply and demand. Like the actual consumers, students, and sometimes teachers often don't have a lot of choice when it comes to textbooks, which I think limits innovation and also makes them artificially expensive. The truth is, I have no idea how this will shake out. I'm terrible at predicting the future, but I will say this. I got a C- in 10th grade geometry, which, if anything, was generous, and I've always been really embarrassed about not understanding even the basics of high school math. I had good teachers, but they had a lot of students, and I just couldn't get it from the textbook. But then, at the age of 41, I worked my way through math-a-guns geometry courses with some help from a real-life math teacher, and while I was learning, I kept being like, oh, wow, cool! Now I understand how tessellations work, and that makes me optimistic in spite of it all. Hank, I'll see you on Friday.