It’s truffle season, and prices for the highly sought-after white truffles soared this year to around $4,000 per pound. The market is the subject of the documentary “The Truffle Hunters,” as well as Rowan Jacobsen’s book, “Truffle Hound.” We spoke to Jacobsen about the evolving, but still foggy, truffle market. In keeping with books, we also discuss the Federal Reserve’s Beige Book, which serves as an economic snapshot through the lens of regional banks.