Where to leave your discarded books

When I finish a book, I dislike keeping it, unless I expect to read it again.  My Russian wife claims I throw things out for the sake of the action itself; she is right.  I also enjoy giving books away.  But when you are traveling, who should receive the book?

At times I engage in serendipitous fantasy, by leaving the book on a park bench and imagining what might happen to it, how seditious ideas might change lives around the globe.  But lately the practical economist in me has taken over.  How should I discard books so as to maximize social welfare?

In Singapore I tried leaving a book -- a slightly salacious one at that -- in the public library.  Surely it will be found there.  But will anyone be allowed to check it out?  Alternatively, you might think that the greatest number of people will see it in a crowded train or bus station.

One radical option is to leave the book, well...in a bookstore.  Most likely, the book will be sold.  If you bring it to the counter they will be puzzled but I suspect will be willing to ring it up and punch in a code.

Of course now the book has a price, which can restrict the chance it is ever read.  But the chance of it getting into the right hands -- the high-valuing user -- has gone way up.  This is a testament to the role of middlemen in a capitalist economy.  The book is probably worth more to the world at full price, in a bookstore, than lying on a bench for free.

So now you know where to leave your discarded books.