Comic Grade vs. Age: Census Data
So at this point most everyone is familiar with CGC and CBCS census data, so what I thought would be an interesting exercise would be to pick a selection of books from the Golden Age through to Modern and see how the grades compare and whether there were any trends to be observed. In addition to see at what grade the 35% threshold is met. While somewhat arbitrary a number of people indicate that for investment grade books you want the grade to be in the top 35% of the census population. For some books this type of approach obviously makes sense, however for others the old saying "low grade > no grade" is still most appropriate. So lets start with some information and a few charts.
The first simply shows the census numbers for a bunch of popular books all on the same plot (note that the dashed lines are on the second Y-axis, ie the one on the right). What this shows is where the weighting is for various books and in general by "age". For instance the early SA books tend to have a greater quantity of lower grade books with a mean of about 3.5, late SA around 4.5, BA around a 7.0, and MA around a 9.2. What is interesting is that the grade allocation regardless of book follows the comic age pretty well so even though the number of books on the census may be different the general trend looks nearly the same based purely on the age of the book. And while it is intuitive, it can also be seen quite clearly, that the newer the book the higher the grades on the census as well as the greater the total number of books on the census. Does this hold true for all books, not exactly but it does seem to hold true for many of the most popular "investment" type books. Low population books, such as many GA books, likely wont fit the trends because there simply aren't enough of them, but the general trends should apply to most any book that has at least a few hundred books on the census.
This brings us to our second chart. This chart shows the same books but by percent of books in a higher grade, so in a 0.5 100% of the other books are in a higher grade, while at a 9.8 (assuming no 9.9) 100% of the books have a lower grade. Again what is interesting is the grouping of books. Moderns skew towards the 9+ and are grouped regardless of book, the BA are similarly grouped, as are the SA though the grades on SA improve based on the year, so there are really two groupings for SA, early and late. The red line sits at the 35% line which means that any book below the line is in the top 35% percent for that book (often times this is a good threshold to use if the book is viewed as an "investment" piece). Note that this doesn't mean a lower grade is a bad investment or wont yield positive returns, its just a guide. However what it clearly shows is that if you follow the 35% rule (or any set threshold) that for a Showcase 22 that any grade above a 4.0 would qualify whereas for a BA grail the grade would jump to around an 8.5, and for a modern it jumps to about a 9.6. So what does this all mean with regards to buying and selling books, not much perhaps but it can give some insight into the relative populations and trends and how "rare" a book might be in a specific condition in comparison to others. It can also highlight just how much of a difference a few grades might make for one book vs another. Collecting should always be about what you like and what you can afford, however if you can also spend your money "wisely" that never hurts either.