Circulating Reference Books

If your library is like mine, the use of print reference sources has declined dramatically over the past several years.  Since fewer patrons are using these materials, I am thinking of rewarding those that do by letting them check them out.  I already give special permission to just about anyone who asks me if they can check out a reference book, so I am thinking about making this a standard policy and making all reference books available for a 24 hour loan.

My thinking behind this has always been that I would rather have a book taken out and used by a patron than sitting unused on our library shelves.  When I proposed this to the other librarians in my department, it was viewed as a radical departure from existing procedure.  I do understand that there is a risk of letting expensive reference books go out of the building, yet at the same time I feel that we buy them to be used.  If they are not used much in the building, why not let people take them home?

What are your thoughts on giving all reference books a standard 24 hour loan period?