It is standard practice to ask applicants for academic jobs – at least for jobs in philosophy – to submit reference letters. Yet, an increasing number of people have been recently expressing scepticism about the practice. (See, for instance, the comments to this blog post.) This may be a good time for public discussions about it; the present post is a sketch of the pros and cons of using letters of reference in the process of selecting people for academic jobs in philosophy.
One worry with hiring on the basis of reference letters is that this tends to reinforce the regrettable importance of 'pedigree' – that is, of the university where candidates got their doctoral degree and of the people who recommend the candidate. There are relatively few permanent jobs in the current job market, and significantly more qualified candidates than jobs, whether permanent and temporary. One consequence is that there are many (over-)qualified candidates for (almost?) each job, and making the selection process really difficult. Considering dozens, sometimes hundreds, of applications for one position is an onerous task, so it is appealing to take pedigree into consideration because this is an expedient method to decide whom to short-list or even whom to hire. (As I mention below, this doesn't mean expedience is the only appeal of relying on pedigree.) But this is unfair to candidates: those who weren't supervised by influential letter-writers, or who otherwise didn't make their work sufficiently know to an influential letter-writer, have fewer chances on the job market. Moreover, relying on letters of reference can also be bad for quality, to the extent to which letters fail to closely track merit. This kind of problem will not entirely go away just by eliminating reference letters – the prestige of a candidate's university will continue to matter – but its dimensions would be more modest.
Another worry is that reference letters reflect and perpetuate biases, perhaps unconscious ones, against members of groups that are under-represented in philosophy for reasons of historical or present discrimination, such as women or racial minorities. There are studies suggesting that reference letters written for female candidates tend to make recommendations in terms less likely to ensure success than those used in letters recommending male candidates. If this is true, letters of reference can, again, be unfair.
Another group of reasons to give up reference letters has to do with avoiding corruption – of the hiring process and of personal relationships within the academia – and their unhappy consequences. As long as they are used in hiring, reference letters are highly valuable assets. Those able to write the most influential letters can treat letters as tokens in exchange for illegitimate benefits from the candidates they recommend. Hiring without reference letters would diminish the potential of unfairness towards candidates who resist such exchanges, and the likely unfairness towards others when they don't. At the same time, it would eliminate one source of illegitimate power of letter writers over the candidates they recommend. To depend on a supervisor, or on other powerful people in the field, for a reference letter seems to in itself undesirable: a relationship in which one person has enormous power to make or break another's career looks like a relationship of domination. But even if it isn't, there might be a good reason against such dependency: to protect the possibility of genuine friendships between established and budding academics. Genuine friendships are more difficult to flourish when structural conditions make it likely that people who pursue the relationships have ulterior motives. It is great not to have to worry that your professor cultivates your company because they want from you something they could ask in exchange for a reference letter. It is great not to worry that your student or younger colleague cultivates your company because they hope you'll give them a good letter. (Not all such worries will be averted by giving up on reference letters; one can and some do advance their students' careers by unduly facilitating for them publications in prestigious venues or by over-promoting them.)
Finally, there are reasons of general utility to hire without reference letters: Writing them takes time and, unlike other writings, they rarely have value beyond getting someone hired (and it's not the most exciting way to spend one's time). Interpreting reference letters properly can also be a drag in the context of praise inflation. And it is stressful to ask people to write letters recommending you. Admittedly, these are not, in themselves, very strong arguments, but they should nevertheless count in an overall cost-benefit analysis of reference letters.
All this is not to say that there are no advantages of having reference letters in the hiring process. They may be useful proxies to determine that a candidate received proper philosophical training: in philosophy, at least, we learn an awful lot by simply seeing how others do good philosophy, and being allowed to participate in the process. The mere fact that one has been taught by a respected philosopher should count for something. But, in fact, in this day and age it is becoming increasingly easy to witness good philosophy independent from who mentors you. There are numerous conferences, and it became easier to travel to them; the internet is turning into an inexhaustible source of filmed philosophical events. Almost everybody can study the best philosophers in action, and many can interact with them on a regular basis at philosophical events. These philosophers will continue to feel particularly responsible towards their own students' careers (and so write letters for them) but, thanks to contemporary media, they can benefit an ever higher number of students in philosophy. Of course, search committees will not know which candidates who were not taught by the most prestigious philosophers did in fact benefit from the easily available resources (conferences, recordings of lectures and other events.) But nor can they assume a wide gulf between candidates who have and candidates who have not been taught by very respected philosophers.
A very important function of reference letters is, to my mind, that of giving prospective employers a way to check certain aspects concerning candidates, in case of doubt. This pro is specific to references, and as such has nothing to do with pedigree. Is a prospective employee a good team player? How much did she contribute to a particular publication? How close to publication are the papers listed on a c.v. as 'in progress'? But this aim can be satisfied in the absence of a general requirement that job applications include letters. It is enough if candidates are asked to list, in their application, a few people who can comment on them, with the understanding that referees are only to be contacted occasionally/exceptionally.