One natural way to get more talent into EA organizations is to offer internships. Internships require only short-term commitment, and people can be much more exploratory about where they intern than about where they accept full-time jobs. Given that, I want to hear from people in EA organizations: what are the most important considerations in deciding whether or not to offer an internship? And why do so few EA organizations offer internships?
I am most familiar with the case of GHD, where no organizations regularly offer internships other than OP itself. The EA internships board has a number of interesting opportunities, but only some of them are in EA organizations.
Sure, we're just not hiring for the same role repeatedly or on a predictable schedule, especially not entry-level roles. Like other orgs, we do work tests and trial periods, which are the fit-testing part of the hiring procedure. We often hire for pretty specialized roles, usually not entry-level, and right now we don't necessarily know the next role we're going to hire for, so we don't know what we'd want to look for in an intern. Those trial periods are useful lead-ins for the specialized jobs we've recently filled, they're just not what I would call an internship. When I think of internships-as-work-training, I think of the model at consultant, financial, or engineering firms, which know they're going to bring in new staff each year to fill entry-level roles that are very similar to each other, because they have a steady stream of work that fits a pattern into which they can predictably slot new people over the course of a year.
As David mentions below, 1Day also does periodically employ students or very early-career people for specific projects, which can look pretty similar to a paid internship in practice. But we can't know that we'll have a suitable full-time role available by the time those contracts are up. Basically, we sometimes do things that look like internships (and sometimes we even call them internships) and we also have a trial period for jobs, but there's not good overlap between what we have interns/student contractors do and what we've hired for lately.