Numbers Game: Books or Beer?

If a picture is worth a thousand words, what's a picture of words worth?

This month's Harper's Index featured a fascinating snapshot (see photo), in just a few lines, of a current trend in book publishing:

Percentage change in the past twenty-five years in the Consumer Price Index: +41

In the price of beer: +40

Of books: -1

I'm no economist, but what I think this suggests is that beer — formerly the low-brow, blue collar swill of the proletariat — is becoming pricier and, with the rise of craft brewing and "better beer," perhaps, more high-brow. So what's that say about books?

Would love to hear your analysis.