Why do they keep the books wrapped in Mexican bookstores?

Yes, wrapped.  So you can’t page through them and see what the book might be like.  I can think of a few hypotheses:

1. They don’t want you standing in the bookstore reading the thing, rather than buying it.  A bit like some U.S. comics news stands in days past.  Yet this doesn’t seem so plausible for longer books or most novels.

2. They want the books to look nicer and less grimy.

3. How about price discrimination?

Imagine there are two classes of readers.  The first is poorer, and only buys books when he or she knows the book is truly desired.  Harry Potter might be an example of such a book.   You want to read what everyone else is reading, to talk about it at school, and you don’t need to scrutinize p.78 so closely before deciding to purchase.

The second class of buyer is wealthier and usually will be buying (and reading) more books, indeed for those people book-buying is a significant habit.  That buyer wants to be on top of current trends, wants to have read whichever book is “best” that year amongst the trendy set, and so on.  If book quality is uncertain, such individuals will end up paying a de facto, quality-adjusted higher per unit price per book.  If you can’t sample the books in advance, you will end up buying some lemons, and you can’t just pick out the cherries.

Wrapped books thus extract more surplus from the second class of buyer and do not much discourage the first class.  The general point is related to the economic analysis of bundling and also block-booking — you have to buy a whole bunch of items to get the things you want.

I wonder if they would mind if I removed the wrapping to take a look before purchasing?  Maybe the store employees would be indifferent, but how about the retail outlet CEO?  The publisher?  The author?  Model this!