17 April 2015, with 2020 post script

Is it a waste of time producing an index for a book when lengthy works are appearing more and more in searchable electronic format? I implied, rather carelessly, that the answer to this question is ‘yes’ in the course of explaining why, as a rule, I intend in future to publish only on my website, in searchable PDFs. (This was, of course, only one of many reasons I offered for this decision.) However, having recently been required to complete another long and complicated index for the new edition of my textbook (usefully reproduced in the ‘sample chapter’ on the Palgrave website here), I was reminded of just how valuable the exercise is. A good analytical index not only sifts the important from the trivial but also provides cross-references between subjects (‘see also …’) and sometimes even a primer in synonyms (‘going native, see localitis’) and pseudonyms (‘Cornwell, David, see le Carré’). This is why it is so depressing to see the spread of books with shoddy indexes, and sometimes only ‘Name Indexes’ – or no index at all! It is also worth noting that indexing is likely to produce a book with fewer mistakes, since it requires what is in effect a second and in some ways more searching reading of the proofs. When indexing my manuscripts, I always find some typos and the odd inconsistency (‘pre-negotiation’ here, ‘prenegotiation’ there) that have been missed both by the copy editor and by my own proof-reading.  Preparing a proper index can take many days, and I am well aware that most young scholars are today under too much pressure to be able to afford the time. For those unable or unwilling to do it themselves, therefore, my advice would be to negotiate with the publisher on the point: try waiving the royalty (always miserly anyway) if, in return, they will pay for a professional job. Alternatively, visit the excellent site of the Society of Indexers, and explore hiring directly. A book with a first-class index (always likely to create a good impression on a busy reviewer) will probably be worth far more to you in the long run than what you will save by doing without one.
PS, 9 November 2020: In her excellent article ‘Indexers, all about’ (The Author, Autumn 2020), the professional indexer, Paula Clarke Bain, says that, at Society of Indexers recommended rates, an index for a ‘straightforward’ 50,000 word book would cost £390.