A manuscript firmly inside one discipline is comparatively easy to route: there is an established reviewer pool, a shared vocabulary, and agreed standards for what counts as rigorous. A manuscript that sits between two fields — say, social policy and education, or economics and public health — does not fit that pipeline as cleanly, and editors often notice the friction before anyone else does.

The difficulty is real. A reviewer trained in one of the two fields may be well positioned to assess half the manuscript and underqualified to assess the other half. Finding two or three reviewers who can credibly evaluate the whole submission, rather than just the half that matches their own training, takes longer and sometimes requires reviewers who do not normally work together at all.

That difficulty is also, in a specific sense, a signal worth paying attention to. Work that stays entirely within one field's existing frameworks is easier to evaluate precisely because it is not asking reviewers to hold two different sets of standards at once. Work that genuinely crosses a disciplinary boundary is harder to review for the same reason it can be more valuable: it is not simply applying an existing method to a new setting, it is asking a question that a single field's toolkit was never built to answer alone.

None of this is an argument for lowering the bar on interdisciplinary submissions. It is an argument for editorial patience — recognizing that the extra time interdisciplinary review sometimes takes is a function of genuine complexity, not a defect in the manuscript.