I have been collecting books since 1998.

I collected fairly casually for the first few years usually paying no more than $40-50 for a book … normally $8-15 for most used books. I remember my brother-in-law Jim telling me one time that he had obtained a copy of Charles Frazier’s award winning debut book, Cold Mountain, for $20 and that it was worth $200. A friend of his at a book store had gotten him a copy.

After hearing that, I always wondered if there was a way to predict which books would increase most rapidly in value. And could you buy them at retail value or less before other collectors recognized the value and started buying them up and listing them for high prices?

My job involves optimization and economics analysis. I use spreadsheets everyday to help maximize the income at our plant.

In late 2007, I started to put together a spreadsheet model of what I thought the most important variables for determining potentially valuable books. I wanted to use this to improve my collecting … and add interest to the web site I was developing, www.book-collecting-tips.com.

The mathematical model includes some non-linear equations. I used some recent prices of books to try to validate the model. The model that exists today is similar to the original model but I have added more factors or variables. I have attempted to make the predicted ratings match or be roughly similar to expected future book prices. So if the rating is 50 I am projecting the price of a book to be $50 in about a year.

You would expect that if a book wins an award the mathematical model will increase the rating. Several other factors will increase the rating or even lower it though this is less common.

Another obvious factor affecting book value is the number of copies of the first printing. This is often difficult to determine especially for print runs of less than 50,000. The authors themselves aren’t always told how many of their books were printed.

For books with print runs of over 100,000, publishers will usually advertise this fact as the book is likely to be a bestseller (sell over 100,000 copies).

I am currently working on a graph which will show the relationship of the ratings to actual book prices. I hope to have that ready in early October. Based on the results I may make some minor changes to the model to make it more accurate.

One of the problems I’m running into is that there are often few of the highly rated books available for sale. That can make the price difficult to estimate if there are large differences between a few books listed online.

Leave a Reply