You can work in an applied I/O setting with either degree. As with most disciplines, however, the PhD will provide greater earning potential; and, if it’s applied research you’re interested in, greater autonomy.
Having worked in consulting/technical assistance/training/applied research in multiple sectors, I can safely assert that there is a viable market for I/O degrees. Safe odds are that the sources recommending the MBA are business types who, no offense to them, are at best minimally familiar with exactly what I/O Psychologists do. From HR to organizational development and policy, I/O P