You can require priors in order to make a computation. Your requirement doesn’t cause the priors to magically appear; but you still require them.
I think Benquo means that you need enough observations to have reliable priors.
That’s right—the problem isn’t that you need priors and don’t have them, but that you need those two particular priors, and getting them probably involves enough work to raise your own sanity level quite a bit.
You can require priors in order to make a computation. Your requirement doesn’t cause the priors to magically appear; but you still require them.
I think Benquo means that you need enough observations to have reliable priors.
That’s right—the problem isn’t that you need priors and don’t have them, but that you need those two particular priors, and getting them probably involves enough work to raise your own sanity level quite a bit.