Being on the receiving end of recruitment for accounting candidates, I have seen some exemplar letters from advisors and additional letter writers. But the experience is uneven. I have seen the accounting letters improve over the years, but there is still quite some variance. Variance in letter content of course is to be expected, and informative; but not quite in the approach and the expectations of what a value-added letter writing exercise should aim to achieve. Hence, some observations.
“Good” letters are “informative;” not just “nice” letters, i.e., just “praising” the candidate. Informative letters are evaluative—they are positive; they elaborate on the strengths of the case but also can make some critically constructive comments about the candidate, e.g., to comment on some tough choices that had to be made to re-direct the research at some critical juncture and which may have caused delays (but in the end were the right choices to make). An assessment or a sense of the candidate's "growth potential" is also very important to convey as the letter writer, especially the advisor, sees it and is able to contextualize it.
Therefore, candidates should not normally expect to “see” the letter (or be worried that when they are not allowed to see it, that it is a negative letter). Letter writers who don’t have anything of value to say will normally decline to write one!
Schools should therefore generally structure their recruiting processes such that letter writers can independently submit their letter in an easy-to-follow, not onerous way (just taking a few clicks and a few minutes – voila).
Hence, confidentiality is important. Again, confidentiality is not to be mistaken as a negative signal!
Candidates should select letter writers very carefully. Some of them should at least be able to comment in detail on the work/research. (I’d say, two out of three of the letter writers if not all three.) Others may be less so, but then they still should have something substantive to say about another dimension of the portfolio or profile (e.g., teaching or citizenship/collegiality). Ideally, but not necessarily, among the three letter writers there is some complementarity in addition to each letter being individually and somewhat uniquely informative because everyone writes their own letter (see also: the anecdote in the penultimate paragraph below).
Letter writers should state why they cannot comment on one or some aspects of the candidate’s profile. For example, I am sometimes asked to write a letter because I can comment on the teaching (as a Head of Department) but I have not otherwise been sufficiently close to the candidate’s research. I then just state this clearly. Not stating it may lead schools to infer that the letter writer is “avoiding” to speak on something (research in the example given) because s/he has not much good to say about it. Don’t leave the reader guessing.
When commenting on the research, letter writers should say something substantive about it. This can be critical, but should be very informative. For example, having used a particularly difficult methodology or having done much hand-collecting of hard-to-get or hard-to-code data can easily (and positively) help explain why it took an extra year to graduate (and how this is a good thing!). It is helpful to contextualize the research (although not in an excuse-making sense), and say something about how things worked out (or not) along the way—things that the recruiting schools cannot always infer from the road paper!
Applicants should therefore inform the letter writers well/fully, and well in advance. Letter writers are busy people and cannot be expected to write an informative letter to be submitted the next day. Again, good letters are informative. To write an informative letter takes time.
The information provided by the applicant to the letter writer should include a CV, the principal paper(s) of the dissertation (and other working papers that will be part of the package), the candidate’s statement, and a list of the schools where the applicant intends to apply with a link to the job advertisements, plus ideally already information where and by when to submit the letter for each school, and other details, such as the addressee (for the letter’s salutation) and his/her address which the letter writer can copy-and-paste into the letter. In other words, the applicant should deliver a well-prepared package to the letter writer. Make the letter writer focus on the content, and make everything else as easy and as least onerous as possible for the person who has agreed to help you.
Schools should endeavor to streamline their letter requests, again, having an (online) application process where letter writers can conveniently submit their letters independently from the candidate’s own submission of the application package.
If the applicant ends up seeing the letter (e.g., because the schools where they are applying are having an antiquated process, expecting the applicant to include the letters in their package), then the applicant should treat the letters with utmost professional restraint and in the greatest confidentiality. For example, they should not use it for any other purpose than on this round of job applications and should not give it to anyone else other than the school(s) they told the letter writer it was intended for. They should not brag about the letter, nor show it to anyone. Confidentiality has to mean something! As an anecdote, I was once sent the letter from another letter writer by the applicant as an “example” for me to write my own letter—maybe expecting that I would only change some trivialities and the signature (?). This is not done! Not done! I would not respond well when I were to find out that my own letter would be sent around to other letter writers as an example. Candidates should also not write a “template” letter for the letter writer to tweak. All this flies in the face of what should be a serious practice of letter writing.
In conclusion, good letters require that ALL parties act professionally and responsibly: the CANDIDATE, the RECRUITING SCHOOL, and the LETTER WRITER. If they (or any one of them) don’t, letter writing fulfils no useful purpose. If it is perceived like that, then of course letter writers will not invest. Then the letters become perfunctory. In other words, it establishes a NEGATIVE EQUILIBRIUM rather than the positive it is intended to be, or could be.