As another commenter pointed out, the library will still automatically charge a "replacement fee" if the book is 30+ days overdue. That fee may be subsequently refunded if the book is eventually returned.

That to me seems like the best incentive: you are automatically charged what is still essentially a "late fee" at some point, and that charge goes away if you return the item.

https://www.nypl.org/help/borrowing-materials/library-fines-...